Question

The average rate of the first part of Yi’s walk on a park loop was 4 miles per hour. She then met up with a friend and the two walked the rest of the way at an average rate of 5 miles per hour. The entire 3-mile walk took Yi 42 minutes (0.7 hour). Which equation can be used to solve for x, the time in hours that Yi spent walking before meeting her friend? x = 0.7 – x x + (0.7 – x) = 1 4x + 5(0.7 – x) = 1 4x + 5(0.7 – x) = 3

Answer 1

4x + 5(0.7 – x) = 3

Explanation:

Answer 2

Total distance covered = 3 miles.

First part walked at the rate 4 miles per hour.

Let us assume x hours was walked in first part.

Total distance covered in x hours at the rate 4 miles per hour = 4x.

Second walk rate with meet with friend = 5 miles per hour.

Total time taken = 0.7 hours.

Therefore, time taken in second walk only = (0.7 - x) hours.

Distance covered in second walk = 5 (0.7 - x).

Total distance covered = distance covered in first part + distance covered in second part.

4x + 5 (0.7 - x) = 3 miles.

Therefore, correct option is 4x + 5(0.7 – x) = 3.