A town has accumulated 5 inches of snow, and the depth is increasing by 6

inches every hour. Another town has accumulated 9 inches of snow, and the depth is

increasing by 3 inches every hour.

How long until the snowfall in both cities is equal?

A. 1 hour and 20 minutes

B. 1 hour and 33 minutes

C. 45 minutes

D. 1 hour 15 minutes

Therefore, after 1 hour and 20 minutes, the snowfall in both cities was equal to 13 inch.

Step-by-step explanation:

Calculating the depth of First Town:

First town has accumulated 5 inches of snow.

As the depth is increasing by 6 inches every hour

i. e. 6 inch = 1 hour

so the depth increase after 45 minutes i. e. 3/4 hour = 4.5 inch

so

After 45 minutes

Snow level of First town after 45 min = 4.5 + 5 = 9.5 inch

After 1 hour

Snow level of First town after 1 hour = 5 + 6 = 11 inch

After 1 hour and 20 minutes

5 + 6 + 2 = 13 inch ∵ If 6 inch per hour, then 2 inch in 20 min

Calculating the depth of Second Town:

Second town has accumulated 9 inches of snow.

As the depth is increasing by 3 inches every hour.

i. e. 3 inch = 1 hour

so the depth increase after 45 minutes i. e. 3/4 hour = 2.25 inch

so

After 45 minutes

Snow level of Second town after 45 min = 9 + 2.25 = 11.25 inch

After 1 hour

Snow level of Second town after 1 hour = 9 + 3 = 12 inch

After 1 hour and 20 minutes

Snow level of Second town after 1 hour and 20 minutes

9 + 3 + 1 = 13 inch ∵ If 3 inch per hour, then 1 inch in 20 min

From the above observation, it is clear that after 1 hour and 20 minutes the snowfall in both cities was equal.

Therefore, after 1 hour and 20 minutes, the snowfall in both cities was equal to 13 inch.