Question

Laura can finish payroll in 3 hours. it takes ben 5 hours to do the same job. If they work together, how long should it take them?

Answer 1

15/8 hours .................

Explanation:

Let L be Laura, and B be Ben. Then:

3L=1

5B=1

Next:

15L=5

15B=3

15(L+B)=5+3=8

15/8 (L+B)=1