Question

Three siblings- Kate, Sarah, and Dave comitted themselves to volunteer 160 hours for a homeless charity to build new housing. Dave worked 15 hours more than Kate. Sarah worked 20 hours fewer than Kate. How many hours did each of these siblings volunteer?

Answer 1

Kate 55 hours

Dave 70 hours

Sarah 35 hours

Explanation:

Let k be Kate's hours

Dave = 15 + k

Sarah = k- 20

Dave + Kate + Sarah = 160

15 + k + k + k - 20 = 160

3k - 5 = 160

3k = 165

k = 55

Kate worked 55 hours

Dave worked 70 hours

Sarah worked 35 hours