Mrs. leonard can grade 8 math test in 10 minutes. how long will it take her to grade 72 math test? i need answers

90 minutes (1 hour and 30 minutes)

Step-by-step explanation:

Using cross-multiplication, I wrote down the equation 8 tests / 10 mins = 72 tests / x minutes. After cross multiplying, you'd get 720 = 8x. To get the answer, you'd then divide 8x and 720 by 8 to isolate the x, wounding up with 90 minutes.

Hope this helped!

- "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."