It takes Amy twice as long to deliver papers as it does Nancy. How long, in minutes, would it take each girl to deliver the papers by herself if they can deliver the papers together in 20 minutes?
A) 20 minutes for Nancy and 40 minutes for Amy
B) 40 minutes for Nancy and 20 minutes for Amy
C) 30 minutes for Nancy and 60 minutes for Amy

Question

Quizplus · Accepted Answer

If Nancy takes x minutes, Amy takes 2x minutes. Together, their rate is 1/20 papers per minute. Solving 1/x + 1/(2x) = 1/20 gives x = 30, so Nancy takes 30 minutes and Amy takes 60 minutes.

It Takes Amy Twice as Long to Deliver Papers as It