Sara worked 22 hours last week. Joan worked 4 hours less than Sara, and Erin worked half as many hours as Joan. How many hours did Sara, Joan, and Erin work last week?

SO basically Sara worked for 22 hours and Joan worked for 18 hours and Erin worked for only 9 hours. 22 + 18 + 9 = 49 hours in total.

Sara worked 22 hours Joan worked 18 hours Erin worked 9 hours The three of them worked 49 hours in total

Explanation:

You may set a numerical equation by translating the word statements into arithmetic expressions in this way:

1) Sara worked 22 hours last week: 22

2) Joan worked 4 hours less than Sara: 22 - 4

3) Erin worked half as many hours as Joan: [22 - 4] / 2

4) How many hours did Sara, Joan, and Erin work last week? : add up every arithmetic expression:

22 + (22 - 4) + (22 - 4) / 2

5) Simplify doing the operations:

22 + (22 - 4) + (22 - 4) / 2 = 22 + 18 + 18/2 = 22 + 18 + 9 = 49

Conclusion:

Sara worked 22 hours Joan worked 18 hours Erin worked 9 hours The three of them worked 49 hours in total.