Problema Solution
A painter can finish painting a house in 7 hours. Her assistant takes 9 hours to finish the same job. How long would it take for them to complete the job if they were working together?
Answer provided by our tutors
1 hour work of painter 1/7
1 hour work of assistant 1/9
total 1 hour work = 1/7 + 1/9 = 16/63
so they both complete in
63/16 = 3 15/16 hours