Question

David drove 70 miles in the first 1 ¾ hours of his trip. how much longer should it take him to drive an additional 120 miles if he drives at the same average speed?

Answer 1

Let us first calculate the average speed of David,

Av speed = Distance traveled/ Time taken

We have, distance = 70 miles

Time = $1\frac{3}{4}$ hours = 1.75 hours

Av speed = $\frac{70}{1.75}$

= 40 miles/hour

Another 120 miles will be traveled in time, t = 120/40 = 3 hours