The Sanchez family drove 132 miles in 3 hours before lunch. Then they drove 240 miles in 5 hours after lunch.

What was their average speed for the day?

A.

46 mi/h

B.

54 mi/h

C.

54.5 mi/h

D.

46.5 mi/h

The formula for speed is the total distance traveled over time. We shall calculate the 2 speeds individually - before and after lunch. Afterwhich, we shall add them together and divide by 2 to get the average.

Before lunch s = 132 mi / 3 hr = 44 mi/hr

After lunch s = 240 mi / 5 hr = 48 mi/hr

Ave s = 48 + 44 / 2

Ave s = 46 mi/hr

Therefore the correct answer is A.