Mr. A buys an article and sells it to Mr. B at a profit of 10%. Mr. B sells it to Mr. C at a gain of 20%. If C paid
Rs. 924 for it; what did Mr. A pay for it?

- "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."

i think the amount would be $140.62

80x^8−68x^6+16^5−20x^4−4x^3+8x^2

hope i'm right lol