Question

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? Group of answer choices

Answer 1

x=3 15/16 hours together

Explanation:

the painter paints 1/7 of the house in 1 hour

the assistant paints 1/9 of the house in 1 hour

x=# of hours it takes them together to paint the house

(1/7)x+(1/9)x=1 (job finished)

multiply both sides by the LCM which is 63

63(1/7)x+63(1/9)x=63(1)

9x+7x=63

16x=63

x=63/16

x=3 15/16 hours together