Question

On a trip, a car traveled $80$ miles in an hour and a half, then was stopped in traffic for $30$ minutes, then traveled $100$ miles during the next $2$ hours. What was the car's average speed in miles per hour for the $4$ -hour trip?

$45$

$50$

$60$

$75$

$90$

Answer: A

Concepts:distance rate and time

Difficulty rating: 930

Solution:

The car covered $80 + 100 = 180$ miles in total, over $1.5 + 0.5 + 2 = 4$ hours (the traffic stop still counts as time).

The average speed is $\dfrac{180}{4} = 45$ miles per hour.

Thus, the correct answer is A .

1992 AMC 8 Problem 18

Answer: A

Solution:

Problem 18 in Other Years