10 people can paint a building in 5 days. If each person paints as quickly as the others then how much of the building could 7 people paint in 5 days?
7/5 🤔
❌❌ Incorrect ❌❌
5/7 🤔
✅✅ Correct !!
10 people can paint a building in 5 days. Each person paints 1/10 of the
building in 5 days. In 5 days 7 people would paint 7 × 1/10 of the
building In 5 days 7 people would paint 7/10 of the building.
7/10 🤔
❌❌ Incorrect ❌❌
10/7 🤔
❌❌ Incorrect ❌❌
How many meters are there in 21 feet?
6.4615 🤔
✅✅ Correct !!
3.25 feet = 1 meter
1 foot = 1÷3.25 meters
21 feet = 21×1÷3.25 = 6.4615 meters
646.15 🤔
❌❌ Incorrect ❌❌
6825 🤔
❌❌ Incorrect ❌❌
68.25 🤔
❌❌ Incorrect ❌❌
What is the x value such that y =15 – 3x and y = 0?
15 🤔
❌❌ Incorrect ❌❌
5 🤔
✅✅ Correct !!
y =15 – 3x and y = 0
Hence 15 – 3x = 0
Hence 3x = 15 x = 5
3 🤔
❌❌ Incorrect ❌❌
0 🤔
❌❌ Incorrect ❌❌
Put these four fractions in order from smallest to largest: 1/4, 2/3, 4/7, 1/2
1/4, 1/2, 4/7, 2/3 🤔
✅✅ Correct !!
If 1/4, 2/3, 4/7, 1/2 are converted to decimals we get 0.25, 0.6666….,
0.571….., 0.5 then the correct order is obvious
or
If 1/4, 2/3, 4/7, 1/2 are converted to fractions with a common denominator
21/84, 56/84, 48/84, 42/84 then the correct order is obvious.
1/4, 1/2, 2/3, 4/7 🤔
❌❌ Incorrect ❌❌
1/2, 2/3, 1/4, 4/7 🤔
❌❌ Incorrect ❌❌
1/4, 4/7, 1/2, 2/3 🤔
❌❌ Incorrect ❌❌
On a number line what is the distance between -3/7 and -2/3 ?
23/21 🤔
❌❌ Incorrect ❌❌
1/4 🤔
❌❌ Incorrect ❌❌
5/21 🤔
✅✅ Correct !!
The distance between numbers can be found by using absolute values (|a| or
abs(a)).
The distance between these numbers is abs(-3/7 − -2/3 )
= abs(-(3/7 -2/3))
= abs(3/7 -2/3)
= abs(9/21 – 14/21)
= abs(-5/21 )
=5/21
-23/21 🤔
❌❌ Incorrect ❌❌
An isosceles triangle has two equal sides. If two of the sides are 5 inches and 2 inches, what is the perimeter of the triangle?
19 inches 🤔
❌❌ Incorrect ❌❌
12 inches 🤔
✅✅ Correct !!
The other side must be 5 inches otherwise the two shorter sides could not
meet.
The perimeter is the distance around the outside of the triangle and is 5
+ 5 + 2 = 12.
10 inches 🤔
❌❌ Incorrect ❌❌
None of the above 🤔
❌❌ Incorrect ❌❌
The cylinder below has r = 10 inches and a volume of 6283 cubic inches to the nearest cubic inch. Find the height of the cylinder to the nearest inch.
25 inches 🤔
❌❌ Incorrect ❌❌
3 inches 🤔
❌❌ Incorrect ❌❌
10 inches 🤔
❌❌ Incorrect ❌❌
20 inches 🤔
✅✅ Correct !!
The volume of this cylinder is 6283.
(pi)r2h = 6283. h is the height. (pi) is 3.14…
h = 6283÷(pi)÷100 = 19.999…. h = 20
The height of the cylinder is 20 inches.
A rocket on a computer screen has a path modeled by the equation h=-t2+3t+10 where t is time in seconds and h is the height above a platform and is in computer units. Find how long the rocket takes to reach the platform.
2 seconds 🤔
❌❌ Incorrect ❌❌
10 seconds 🤔
❌❌ Incorrect ❌❌
12 seconds 🤔
❌❌ Incorrect ❌❌
5 seconds 🤔
✅✅ Correct !!
The platform is reached when h = 0. It is necessary to solve the equation
0 =-t2+3t+10. This can be rearranged to t2-3t-10 = 0. Hence (t – 5)( t +
2) = 0.
Solving the equation gives t = 5 or -2. As t is a time it is not possible
for t to be -2. The rocket takes 5 seconds to reach the platform.
In the diagram below, which line has a positive slope?
AB 🤔
❌❌ Incorrect ❌❌
AD 🤔
❌❌ Incorrect ❌❌
AC 🤔
✅✅ Correct !!
The coordinates of A are (1,2), the coordinates of B are (3,2). The slope
of AB is (2-2)/( 3-1) = 0
The coordinates of A are (1,2), the coordinates of D are (-2,4). The slope
of AD is (4-2)/( -2-1) = -4/3
The coordinates of A are (1,2), the coordinates of C are (2,4). The slope
of AB is (4-2)/( 2-1) = 2
The coordinates of D are (-2,4), the coordinates of B are (3,2). The slope
of DB is (2-4)/( 3− -2) = -4/5
DB 🤔
❌❌ Incorrect ❌❌
In the diagram below, what are the coordinates of the mirror image of the point B in the x-axis?
(3,-4) 🤔
❌❌ Incorrect ❌❌
(3,-2) 🤔
✅✅ Correct !!
If B is reflected in the x-axis its x-coordinate will not change but it
will be as far below the x-axis as it currently is above the x-axis.
Its coordinates, after reflection, will be (3, -2)
(-3,2) 🤔
❌❌ Incorrect ❌❌
(2,3) 🤔
❌❌ Incorrect ❌❌
One third of the candidates for a job were 25 years old or younger. Two sevenths of the candidates were at least 50 years old. If 84 people applied for the job, how many were between 25 and 50?
32 🤔
✅✅ Correct !!
One third of 84 is 84 × 1/3 = 84÷3 = 28. 28 people 25 years old or younger
applied for the job. Two seventh of 84 is 84 × 2/7= 2×84÷7 = 24.
24 people who were at least 50 years old applied for the job. 84 – 28 – 24
= 32. 32 people applied for the job who were between 25 and 50.
28 🤔
❌❌ Incorrect ❌❌
24 🤔
❌❌ Incorrect ❌❌
33 🤔
❌❌ Incorrect ❌❌
Which of the following is a factor of 450 and multiple of 25?
30 🤔
❌❌ Incorrect ❌❌
75 🤔
✅✅ Correct !!
It can be confirmed by division that (a), (b) and (c) are factors of 450,
while 100 is not. The multiples of 25 are 25, 50, 75,…. 75 is both a
factor of 450 and multiple of 25
90 🤔
❌❌ Incorrect ❌❌
100 🤔
❌❌ Incorrect ❌❌
The formula h – 15 = 3.2t gives the height h in inches of a plant t weeks
after planting.
Which is the rate at which the plant’s height is increasing?
15 inches per week 🤔
❌❌ Incorrect ❌❌
18.2 inches per week 🤔
❌❌ Incorrect ❌❌
3.2 inches per week 🤔
✅✅ Correct !!
h =15 + 3.2t gives the height of a shrub in inches after t weeks. When
planting occurs the height is 15 + 3.2× 0 = 15 inches
After one week the height is 15 + 3.2× 1 = 18.2 inches
The rate at which the height increases is 18.2 – 15 = 3.2 inches
48 inches per week 🤔
❌❌ Incorrect ❌❌
The formula h -15 = 3.2t gives the height h in inches of a plant t weeks
after planting.
How high was the initial height of the shrub?
15 inches 🤔
✅✅ Correct !!
Initial means at the beginning. At the beginning t is 0. h =15 + 3.2t
gives the height of a shrub in inches after t weeks.
When planting
occurs the height is 15 + 3.2× 0 = 15 inches
3.2 inches 🤔
❌❌ Incorrect ❌❌
18.2 inches 🤔
❌❌ Incorrect ❌❌
11.8 inches 🤔
❌❌ Incorrect ❌❌
The formula h -15 = 3.2t gives the height h in inches of a plant t weeks
after planting.
When was the height 31 inches?
Some time between 11 and 18 weeks 🤔
❌❌ Incorrect ❌❌
Some time between 7 and 12 weeks 🤔
❌❌ Incorrect ❌❌
Some time between 6 and 10 weeks 🤔
❌❌ Incorrect ❌❌
Some time between 3 and 7 weeks 🤔
✅✅ Correct !!
h =15 + 3.2t gives the height of a shrub in inches after t weeks. When the
height is 31 inches 31 = 15 + 3.2t
3.2t = 16
t = 16÷3.2
t = 5
The height is 31 inches after 5 weeks
A graph of the temperature T (degrees Fahrenheit) in a refrigerator t
hours after midday.
What is the equation of the axis of symmetry of this graph?
T = 9 🤔
❌❌ Incorrect ❌❌
t = 3 🤔
❌❌ Incorrect ❌❌
T = 0 🤔
❌❌ Incorrect ❌❌
t = 0 🤔
✅✅ Correct !!
It is clear from the diagram that the T -axis is the mirror line or axis
of symmetry of this diagram. The equation of the T- axis is t = 0.
The equation of the axis of symmetry of this graph is t = 0
A graph of the temperature T (degrees Fahrenheit) in a refrigerator t
hours after midday.
It is necessary to find the times when the temperature is 8o F. Which of
the following is the correct equation to do this.
9 – t = 8 🤔
❌❌ Incorrect ❌❌
9 + t2 = 8 🤔
❌❌ Incorrect ❌❌
9 + t2 = 8 🤔
✅✅ Correct !!
It is apparent from the graph that it is not linear hence the answer
cannot be (A) If an attempt is made to solve (B) it will be found there is
no real solution. One of the solutions to (D) is 8, which gives a negative
value. (C) is the only possible solution.
9t – t2 = 8 🤔
❌❌ Incorrect ❌❌
Which of the following is the equation of the straight line joining the points on the graph corresponding to t = 2 and t = 1?
T + 3t = 11 🤔
✅✅ Correct !!
The point on the graph corresponding to t = 1 is (1,8). The point on the
graph corresponding to t = 2 is (2,5). The slope of the straight line
joining them is (5 – 8)÷(2 – 1) = -3.
The equation is T = -3t + c As (2,5) lies the line we can substitute for t
and T.
5 = -3×2 + c
c = 11
Equation is T = -3t + 11 which is the same as (a)
T – 3t = 11 🤔
❌❌ Incorrect ❌❌
T + 11t = 3 🤔
❌❌ Incorrect ❌❌
T + 3t = 1 🤔
❌❌ Incorrect ❌❌
The formula for the volume V of the sphere = 4(pi)r3 / 3. Which of the following is the closest approximation to the volume when r, the radius, is 11 inches?
6000 cubic inches 🤔
❌❌ Incorrect ❌❌
5590 cubic inches 🤔
❌❌ Incorrect ❌❌
5573 cubic inches 🤔
✅✅ Correct !!
It is necessary to substitute 11 for r in the formula.
The calculation is V = 4/3 x (pi=3.14) x 113 = 5572.45…….
Clearly the closest approximation to this is (c)
5000 cubic inches 🤔
❌❌ Incorrect ❌❌
If the radius of the sphere were doubled by what factor would the surface area be enlarged?
2 🤔
❌❌ Incorrect ❌❌
4 🤔
✅✅ Correct !!
If r = 1 then the surface area of the smaller sphere is 12.56……
If the radius is doubled the surface area is 50.26……
The factor is 50.26… ÷ 12.56…. = 4.
The surface area is enlarged by a factor of 4.
8 🤔
❌❌ Incorrect ❌❌
16 🤔
❌❌ Incorrect ❌❌
 |
 |
Results that senior students from a large high school received in an international mathematics examination.
A pass in this examination is regarded as a mark of 40 or more. How many students in this high school failed to pass this mathematics examination?
167 🤔
✅✅ Correct !!
The mark categories indicating failure are 0-9, 10-19, 20-29 and 30-39. The number of marks in those categories was 23, 32, 45 and 67. 23 + 32 + 45 + 67 = 167.
The number of students who failed the examination was 167.
279 🤔
❌❌ Incorrect ❌❌
187 🤔
❌❌ Incorrect ❌❌
299 🤔
❌❌ Incorrect ❌❌
|
|
Results that senior students from a large high school received in an international mathematics examination.
Which of the following mark intervals contains the highest percentage of students who sat this examination?
30-39 🤔
❌❌ Incorrect ❌❌
50-59 🤔
✅✅ Correct !!
The largest number in a mark interval shown is 128. The interval associated with this number is 50-59. The number of students in the mark interval 10-29 is 32 + 45 = 77. 128 is greater than 77.
Of the mark intervals shown the highest percentage of students who sat this examination was in the 50-59 interval.
10-29 🤔
❌❌ Incorrect ❌❌
90-99 🤔
❌❌ Incorrect ❌❌
|
|
Results that senior students from a large high school received in an international mathematics examination.
What percentage of students who got a mark below 30 got a mark below 20?
23% 🤔
❌❌ Incorrect ❌❌
45% 🤔
❌❌ Incorrect ❌❌
55% 🤔
✅✅ Correct !!
The number of students who got a mark less than 30 was 23 + 32 + 45 = 100. The number of students who got a mark less than 20 was 23 + 32 = 55.
The percentage of students who got a mark less than 30 who got a mark less than 20 was 55÷100 = 55%.
32% 🤔
❌❌ Incorrect ❌❌
|
|
Results that senior students from a large high school received in an international mathematics examination.
The number of students who sat the examination was 466. What is true about the median mark obtained by students who sat this examination?
It lies somewhere from 30 to 39. 🤔
❌❌ Incorrect ❌❌
It lies somewhere from 50 to 59. 🤔
❌❌ Incorrect ❌❌
It lies somewhere from 40 to 49. 🤔
✅✅ Correct !!
As there are 466 students the median will be found by averaging the 233rd and 234th marks, after the marks have been placed in order. Both the 233rd and 234th marks will lie somewhere from 40 to 49.
The average of these two marks will lie somewhere from 40 to 49.
It lies somewhere from 60 to 69. 🤔
❌❌ Incorrect ❌❌
|
|
Results that senior students from a large high school received in an international mathematics examination.
What is the probability that if you randomly picked two students who sat for the examination you would find they both got a mark of 70 or better?
28/466 x 27/466 🤔
❌❌ Incorrect ❌❌
28/466 + 27/465 🤔
❌❌ Incorrect ❌❌
28/466 x 22/466🤔
❌❌ Incorrect ❌❌
28/466 x 27/465 🤔
✅✅ Correct !!
There were 466 students who sat for the examination. The number who got a mark of 70 or more was 28. The probability of the first student getting a mark of 70 or better is 28/466.
The probability of the second student getting a mark of 70 or better is 27/465. The probability of both getting a mark of 70 or better is 28/466 x 27/465 .
Which is the best simplification of (24 x 32) / (2 x 3)?
(24 x 32) / (2 x 3) 🤔
❌❌ Incorrect ❌❌
(23 x 3) / (2 x 3) 🤔
❌❌ Incorrect ❌❌
65 🤔
❌❌ Incorrect ❌❌
23 x 3 🤔
D: (24 x 32) / (2 x 3)= 24-1 × 32-1. 24-1 × 32-1 = 23 × 31 23 × 31 = 23 × 3
Which of the following is the same as (√3 + √2)2 ?
5 + 2√6 🤔
✅✅ Correct !!
(√3 + √2)2 = (√3 + √2)( √3 + √2)
(√3 + √2)( (√3 + √2) =
√3×√3 + √3×√2 + √2×√3 + √3×√3
√3×√3 + √3×√2 + √2×√3 + √3×√3 =
3 + √6 + √6 + 2 =
5 + 2√6
5 🤔
❌❌ Incorrect ❌❌
6 🤔
❌❌ Incorrect ❌❌
5 + 2√5 🤔
❌❌ Incorrect ❌❌
What is the value of (x2 + x + 3) / (x + 2) when x = -1?
1 🤔
❌❌ Incorrect ❌❌
3 🤔
✅✅ Correct !!
(x2 + x + 3) / (x + 2) = ( (-1)2 + (-1) + 3) / ((-1) + 2) when x=-1
5 🤔
❌❌ Incorrect ❌❌
-1.5 🤔
❌❌ Incorrect ❌❌
Which of the following is the same as 10x2 – 11x + 3?
(5x + 3)(2x – 1) 🤔
❌❌ Incorrect ❌❌
(5x – 3)(2x – 1) 🤔
✅✅ Correct !!
10x2 – 11x + 3 = 10x2 – 5x – 6x + 3
(5x + 1)(2x – 3) 🤔
❌❌ Incorrect ❌❌
(5x – 3)(2x + 1) 🤔
❌❌ Incorrect ❌❌
How many ways can 6 people sit on a bench if 3 of them have to sit side by side?
720 🤔
❌❌ Incorrect ❌❌
5040 🤔
❌❌ Incorrect ❌❌
144 🤔
✅✅ Correct !!
Treat the 3 people who wish to sit side by side as a single unit. There are 4 units consisting of three people in the group. The 4 units can be arranged in 4! ways on the bench.
The three people in the group can be arranged in 3! ways. The complete number of arrangements is 4! × 3! = 144.
24 🤔
❌❌ Incorrect ❌❌
This pie chart describes the market share of 5 brands of cleaner, based on a survey of 300 shoppers in New York.
Which 2 brands have similar market shares?
C and E 🤔
❌❌ Incorrect ❌❌
D and B 🤔
❌❌ Incorrect ❌❌
A and D 🤔
✅✅ Correct !!
The market share is in proportion to the sectors. The sectors for A and D are about the same size. A and D have about the same market share.
A and B 🤔
❌❌ Incorrect ❌❌
This pie chart describes the market share of 5 brands of cleaner, based on a survey of 300 shoppers in New York.
45 of the shoppers purchased D. How large is the sector angle for D?
45 degrees 🤔
❌❌ Incorrect ❌❌
60 degrees 🤔
❌❌ Incorrect ❌❌
70 degrees 🤔
❌❌ Incorrect ❌❌
54 degrees 🤔
✅✅ Correct !!
There were 300 shoppers. 45 of them purchased brand D.
The fraction of the shoppers who purchased D was 45/300. The angle for D is 0.15 × 360 = 54 degrees. The sector angle for D is 54 degrees.
This pie chart describes the market share of 5 brands of cleaner, based on a survey of 300 shoppers in New York.
The angle for B is 198 degrees. How many shoppers purchased B?
165 🤔
✅✅ Correct !!
The number of degrees in a circle is 360. The total number of people purchasing cleaner was 300.
The angle for those who bought B was 198. The number who bought B was 198/360 x 300 = 165.
45 🤔
❌❌ Incorrect ❌❌
30 🤔
❌❌ Incorrect ❌❌
198 🤔
❌❌ Incorrect ❌❌
There is a 12% sales tax. The pre-tax cost of a mobile phone is $280. What is the tax payable on this mobile phone?
$28.56 🤔
❌❌ Incorrect ❌❌
$33.60 🤔
✅✅ Correct !!
The sale price of the phone is 0.12×280 = $313.60. The tax is $313.60 – $280 = $33.60.
$312 🤔
❌❌ Incorrect ❌❌
$313.60 🤔
❌❌ Incorrect ❌❌
Given the formula a = s2 + 3b – c , find the value of a when s = 7, b = 13 and c = -24.
77 🤔
❌❌ Incorrect ❌❌
29 🤔
❌❌ Incorrect ❌❌
64 🤔
❌❌ Incorrect ❌❌
112 🤔
✅✅ Correct !!
Substitute for s, b and c.
a = 72 + 3(13) – (-24)
a = 49 + 39 + 24 = 112.
The circle below is divided into eight equal sectors. If a sector is chosen at random what is the probability that the sector contains B or C?
37.5% 🤔
❌❌ Incorrect ❌❌
62.5% 🤔
✅✅ Correct !!
There are 8 sectors. 5 of the sectors contain B or C. 5 out of 8 is 62.5%. The probability that the sector contains B or C is 62.5%
50% 🤔
❌❌ Incorrect ❌❌
75% 🤔
❌❌ Incorrect ❌❌
| Employee | Rate Per Hour | Normal Hours | Overtime Hours | Wage |
| ABC | $25.00 | 26 | x | $850 |
What number should replace x?
4 🤔
❌❌ Incorrect ❌❌
5 🤔
✅✅ Correct !!
For 26 hours they are paid 26×$25 = $650. The money they get for overtime is $850 – $650 = $200.
The number of overtime hours is $200÷$40 = 5.
x is 5.
3 🤔
❌❌ Incorrect ❌❌
8 🤔
❌❌ Incorrect ❌❌
Which of these is true?
√(-3) is negative 🤔
❌❌ Incorrect ❌❌
√(-3) is positive 🤔
❌❌ Incorrect ❌❌
√(-3) is undefined 🤔
✅✅ Correct !!
The symbol for square root is √. The square roots of negative numbers are undefined.
√(-3) is an integer 🤔
❌❌ Incorrect ❌❌
Chong thinks of a number, adds 10 then multiplies the number so obtained by 3 and gets 42.
If the number is n then write an equation for this.
3(n + 10) = 42 🤔
✅✅ Correct !!
Adding 10 to n gives n + 10. Multiplying the number obtained by 3 gives 3(n + 10). Making this equal to 42 gives 3(n + 10) = 42.
3n + 10 = 42 🤔
❌❌ Incorrect ❌❌
42n + 10 = 3 🤔
❌❌ Incorrect ❌❌
10n + 3 = 42 🤔
❌❌ Incorrect ❌❌
For which set of t values is the temperature below 0?
1< t < 3 🤔
❌❌ Incorrect ❌❌
-1< t < 3 🤔
✅✅ Correct !!
Although T is negative for 1 < t < 3, when t= 3 T = 0.
T >= 0 for t >= 3
T > 0 for t < -1.
T < 0 or negative when -1 < t < 3
t >= 3 🤔
❌❌ Incorrect ❌❌
-1< t < -3 🤔
❌❌ Incorrect ❌❌
How many students sat for the two tests?
22 🤔
✅✅ Correct !!
Each dot represents a student. There are 22 dots. The number of students who sat for the tests was 22.
21 🤔
❌❌ Incorrect ❌❌
23 🤔
❌❌ Incorrect ❌❌
30 🤔
❌❌ Incorrect ❌❌
What was the result of the student in the first test whose dot is labeled A?
9 🤔
❌❌ Incorrect ❌❌
8 🤔
✅✅ Correct !!
The coordinates of A are (8,9). The x-coordinate of the point represents the result in the First Test. The x-coordinate of A is 8. The result in the First Test of the student represented by A is 8.
10 🤔
❌❌ Incorrect ❌❌
7 🤔
❌❌ Incorrect ❌❌
Which is true? Points which lie below the line y = x represent all students:
who sat both tests 🤔
❌❌ Incorrect ❌❌
where the results in the Second Test exceed the results in the First Test 🤔
❌❌ Incorrect ❌❌
where the results in the Second Test equal the results in the First Test 🤔
✅✅ Correct !!
The x-coordinate of the point represents results in the First Test. The y-coordinate of the point represents results in the Second Test.
The line y = x will contain points representing students whose results in the Second Test equal the results in the First Test.
If a point lies below this line then it represents a student whose results in the First Test exceed the results in the Second Test.
where the results in the First Test exceed the results in the Second Test 🤔
❌❌ Incorrect ❌❌
A set of 9 numbers {3, 3, 4, 5, 5, 5, 6, 7, 7} has a mean of 5. Another number is added to the set and the mean becomes 6.
What number is added to the set?
15 🤔
✅✅ Correct !!
The total sum of the 9 numbers is 9×5 = 45.
The total sum of the 10 numbers is 10×6 = 60.
45 + number added = 60.
Number added is 60 – 45 = 15.
5 🤔
❌❌ Incorrect ❌❌
10 🤔
❌❌ Incorrect ❌❌
11 🤔
❌❌ Incorrect ❌❌
What is the length of a side of the square?
18 inches 🤔
❌❌ Incorrect ❌❌
9 inches 🤔
❌❌ Incorrect ❌❌
12 inches 🤔
❌❌ Incorrect ❌❌
6 inches 🤔
✅✅ Correct !!
The length of the side of a square is the square root of its area. The area is 36 square inches. The side length is √36 = 6 inches.
What is the perimeter of the shape?
24 inches 🤔
❌❌ Incorrect ❌❌
30 inches 🤔
✅✅ Correct !!
The three sides of the shape which are sides of the square contribute 18 inches to the perimeter of the shape. The sides which are part of the equilateral triangle are each 6 inches long and contribute 12 inches to the perimeter.
The total perimeter is 18 + 12 = 30 inches.
36 inches 🤔
❌❌ Incorrect ❌❌
48 inches 🤔
❌❌ Incorrect ❌❌
The height of the equilateral triangle is 5.2 inches.
Find the area of the shape.
54.8 square inches 🤔
❌❌ Incorrect ❌❌
45 square inches 🤔
❌❌ Incorrect ❌❌
51.6 square inches 🤔
✅✅ Correct !!
The area of the square is 36 square inches. The area of the equilateral triangle is half base times height = ½×6×5.2 = 15.6 square inches. The area of the shape is 36 + 15.6 = 51.6 square inches.
67.2 square inches 🤔
❌❌ Incorrect ❌❌
There are 1,000,000 kb in a GB. Guy has 29 GB of storage on his computer. He has a lot of picture files of about 78kb.
What is the maximum number of such pictures he can store on his computer?
371,795 🤔
❌❌ Incorrect ❌❌
371,794 🤔
There are 1,000,000 kb in a GB. In 29GB there are 29,000,000kb.
Guy can store 29,000,000÷78 = 371,794.87…. pictures. He can store 371,794 complete pictures
400,000 🤔
❌❌ Incorrect ❌❌
300,000 🤔
❌❌ Incorrect ❌❌
Find the length of AC.
10 inches 🤔
✅✅ Correct !!
As ABC is a right angled triangle we can apply the theorem of Pythagoras. The square of the hypotenuse is the sum of the squares of the other two sides.
AC2 = 82 + 62 = 100. AC is 10 inches in length.
9 inches 🤔
❌❌ Incorrect ❌❌
6.9 inches 🤔
❌❌ Incorrect ❌❌
14 inches 🤔
❌❌ Incorrect ❌❌
Which diagram shows a shape whose volume V can be found by the formula V = πr2h ?
Picture A 🤔
❌❌ Incorrect ❌❌
Picture B 🤔
❌❌ Incorrect ❌❌
Picture C 🤔
Students do not have to know formulas for (a), (b) and (d).
The volume of a cylinder is πr2h. This formula is easily obtained by rearranging.
Picture D 🤔
❌❌ Incorrect ❌❌