Speed was increased 20% to 48 mph. What was the speed before the increase

40 mph

Step-by-step explanation:

If the speed increased by 20%, now the speed is 120% of the original speed.

48 mph is 120%, so dividing by 6 will get 8 which is 20%.

If 8 is 20%, you can multiply it by 5 to get 40, which is 100%. This means 40 mph is the original speed.

Hope this helps!

- "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."

a

step-by-step explanation: