Question

Sam and his friend are working at the body shop. Sam can do the work in 7hours. When his friend is helping him they do the same work in 4 hours. How long does it take Sam's friend to do this work alone?

Answer 1

28/3

Explanation:

because 1/7+x=1/4

x=3/28

recipricol of 3/28=28/3

28/3