# Ged Math practice quiz 6 - online test

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

5/7

7/10

10/7

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.

How many meters are there in 21 feet?
Note:
In the metric system of units: 1 meter = 100 centimeters and 1 meter:1 foot = 3.25:1

6.4615

646.15

6825

68.25

3.25 feet = 1 meter
1 foot = 1÷3.25 meters
21 feet = 21×1÷3.25 = 6.4615 meters

What is the x value such that y =15 - 3x and y = 0?

15

5

3

y =15 - 3x and y = 0
Hence 15 - 3x = 0
Hence 3x = 15 x = 5

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

1/4, 1/2, 2/3, 4/7

1/2, 2/3, 1/4, 4/7

1/4, 4/7, 1/2, 2/3

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.

On a number line what is the distance between -3/7 and -2/3 ?

23/21

1/4

5/21

-23/21

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

An isosceles triangle has two equal sides.
If two of the sides are 5 inches and 2 inches how long is the perimeter?

19 inches

12 inches

10 inches

None of the above

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.

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

3 inches

10 inches

20 inches

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

10 seconds

12 seconds

5 seconds

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

AC

DB

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

In the diagram below, what are the coordinates of the mirror image of the point B in the x-axis?

(3,-4)

(3,-2)

(-3,2)

(2,3)

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)