Question 112133
Let x=time it takes Mercy and Eunice working together to prepare a manuscript
Mercy prepares manuscripts at the rate of 1/6 manuscript per hour
Eunice prepares manuscripts at the rate of 1/4 manuscript per hour

Together, they prepare manuscripts at the rate of (1/6)+(1/4)=4/24+(6/24) or
10/24=5/12 manuscripts per hour.  

So the question boils down to the following:

If Mercy and Eunice can prepare 5/12 of a manuscript per hour, how long will it take them working together to prepare 1 manuscript?  So our equation to solve is:

(5/12)x=1  multiply each term by 12

5x=12  divide both sides by 5
x=2.4 hours------------time it takes Mercy and Eunice working together to prepare a manuscript

CK

(5/12)*2.4=1
12/12=1
1=1


Hope this helps---ptaylor