Amy buys 50 computers. she pays £160 for each computer. amy is going to sell some of the computers. she wants to get at least 35% more than she paid for all the computers. she is going to sell each computer for £400. work out the smallest number of computers amy needs to sell

- "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."

m∠a is 90°

m∠b is 40°