Question

The graph shows the number of paintballs a machine launches, y, in x seconds.

Which expression can be used to calculate the rate per second at which the machine launches the balls?

A) 80/4
B) 20/4
C) 4/80
D) 4/20

Answer 1

Divide the y-value by the x-value.

(4, 16)

16 divided by 4 is 4.


The answer is B, 20 balls in 4 seconds. Or 5 balls per second.


Hoped I helped! Please correct me if I'm incorrect.

Answer 2

B) 20/4

Explanation:

Required rate =
`(Number of balls launched)/(Time)`

From the graph, it is evident that (4, 20), (8, 40), (12, 60) and (16, 80) are points.

This means that

20 balls launched in 4 seconds and the rate = 20/4

40 balls launched in 8 seconds and the rate = 40/8 = 20/4

60 balls launched in 12 seconds and the rate = 60/12 = 20/4

80 balls launched in 16 seconds and the rate = 80/16 = 20/4

Hence, the rate per second at which the machine launches the balls is 20/4 and the correct option is (B).