Question

After 5 hours of of house painting, Jess asked the assistance of Jon. Together, they finished the job in 4 more hours. Had Jon joined in an hour after Jess started working, the job would have been finished in 7 hours. How long would it take Jess to paint the house alone?

Answer 1

13 hours

Answer 2

how?

Answer 3

Let J be the rate that jess works, Let T be the rate that they work together

5J +4T = J +6T

Solve for T:
T = 2J, therefore Jess and Jon work at same rate

--> 5J + 4(2J) = 13J

House is painted in 13 hours at Jess's rate