Question

Keitaro walks at a pace of 3 miles per hour and runs at a pace of 6 miles per hour. Each month, he wants to complete at least 36 miles but not more than 90 miles. The system of inequalities represents the number of hours he can walk, w, and the number of hours he can run, r, to reach his goal.
3w + 6r ≥ 36

3w + 6r ≤ 90


Which combination of hours can Keitaro walk and run in a month to reach his goal?

2 hours walking; 12 hours running
4 hours walking; 3 hours running
9 hours walking; 12 hours running
12 hours walking; 10 hours running

Answer 1

Answer. First option: 2 hours walking; 12 hours running

Please, see the attached file for explanation.

Thanks.

Answer 2

A. 2x3=6 and 6x12=72 so 78 is greater than 36

6+72=79 which is less than 90