Ndiba and Asanji are selling wrapping paper for a school fundraiser. Customers can buy rolls of plain wrapping paper and rolls of shiny wrapping paper. Ndiba sold 12 rolls of plain wrapping
paper and 5 rolls of shiny wrapping paper for a total of $157. Asanji sold 3 rolls of plain
wrapping paper and 10 rolls of shiny wrapping paper for a total of $188. Find the cost each of
One roll of plain wrapping paper and one roll of shiny wrapping paper.

i think it would be 42cm

- "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."