Question

Assume that the cheetah travels an average of 40 mph to go from its resting place to a rock near a river. On the return trip to its resting place, the cheetah travels an average of 70 mph. If the cheetah traveled for 15 minutes, how many minutes did the return trip take to the nearest minute and second?

Set up the table as follows. Label the rows “To the River” and “From the River.” Label the columns “Distance,” “Rate,” and “Time (in Hours).” Let t represent the unknown quantity in the problem. Fill in the table.

Answer 1

9.55 minutes

Explanation:

x hours to go to the river

0.25-x hours to come back, since 15 minutes is 0.25 hr.

to the river 40 mph * x hours =40x miles

from the river 70 mph (0.25-x) hours=17.5-70x

those two are equal

40x=17.5-70x

110x=17.5

x=17.5/110=0.159 hours

9.55 minutes