Question

Andy's average driving speed for a 4-hour trip was 45 miles per hour. during the first 3 hours he drove 40 miles per hour. what was his average speed for the last hour of his trip?

Answer 1

3*40 + x / 4 = 45.

The answer of x comes out to be 60. Which means that the speed was travel around 60 miles per hour in the last one hour of the total journey.

Well to understand how i constructed its equation is very simple. I equated the total average speeds answer to 45 and just calculated the average speeds with the help of algebra where x is the number of miles..