Brody invested $7,000 in an account paying an interest rate of 2 3/8% compounded monthly. Robert invested $7,000 in an account paying an interest rate of 2 1/4%
compounded quarterly. After 10 years, how much more money would Brody have in
his account than Robert, to the nearest dollar?

- "runner b is moving at a slower rate."

- "the graphs shown are graphs of distance(km) against time(min).

the slopes of this graphs are are given by:

slope = (change in y)/(change in x)

= (change in distance)/(change in time)

this is the formula for finding the speed. so, the slope of these graphs represent the speed of the runner.

taking each division in the graph to represent 1 on both axis:

runner a ⇒ speed = (2-0)/(1-0)

= 2/1

= 2 km/min

runner b ⇒ speed = (3-0)/(3-0)

= 3/3

= 1 km/min

this shows that   runner b is moving at a slower rate."