Mary can make a costume twice as fast as Sam can. If they both work together, they can make it in 6 hours. How long will it take Mary to make the costume if she works alone?

Question

asked Dec 17, 2021 136k views

1 Answer

Swami · Answer 1 · 2021-12-24T07:00:06+0000

Answer:

If she works alone, it will take Mary 9 hours to make the costume.

Explanation:

The together rate is the sum of each separate rate.

In this problem:

Together rate: 1/6

Sam's rate: 1/x

Mary is twice as fast as Sam, so her rate is 2/x.

Then

(1)/(x) + (2)/(x) = (1)/(6)

(3)/(x) = (1)/(6)

x = 3*6

x = 18

Mary's rate

2/x = 2/18 = 1/9

If she works alone, it will take Mary 9 hours to make the costume.