Let x = the number of hours Eva needs to complete the job and y = the number of hours Emily needs to complete the job
x = 6 1/x + 1/y = 1/4 (The amount of work Eva does in 1 hr + the amount of work Emily does in 1 hr should equal 1/4 of the total work) 1/6 + 1/y = 1/4 1/y = 1/12 y = 12 hours Emily would take 12 hours to do it by herself.
