**Question:**

How many seconds longer does it take to drive 1 mile at 40 miles per hour than at 60 miles per hour?

**Option A):**

15**Option B):**

40**Option C):**

90**Option D):**

60**Option E):**

30

**Correct Answer is Option E):**

30

**Explanation:****Solution:**

Since d = rt , t =d/r. The time required to drive 1 mile at 40 miles per hour is:

t = 1 mile/40 miles per hour = 1/40 hour = (1/40) (60) minutes = 1.5

minutes = (1.5) (60) seconds = 90 seconds

The time required to drive 1 mile at 60 miles per hour is :

t = 1 mile/60 miles per hour = 1/60 hour = (1/60) (60) minutes = 1 minutes = 60 seconds

So it takes 90 - 60 = 30 seconds more to drive 1 mile at 40 miles per hour than at 60 miles per hour.