Chuanxi planned a rectangular sidewalk with a length of 21 ft. he made a scale drawing using a scale factor of 1 in. = 7 ft. he decided to change the length of the actual sidewalk to 27 ft. if the scale drawing still has a length of 3 in., what does 1 in. represent in the new scale?

D which is 9

Step-by-step explanation:

I took the test

- "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."