How Long Will it Take to Make the Quilt?

Date: 21 May 1995 18:48:30 -0400
From: Sandip Mody
Subject: story problem

Adele can make a quilt in 6 days.  Gary in 10 days.  and Sarah in 15 days. 
Adele and Gary work for three days.  How long will it take for Gary and 
Sarah to finish?

I understand that the equation would start our by 3/6 + 3/10 = 48/60 = 4/5

then the equation would be:  x/10 + x/15 = 1/5

Now how would you finish it off?

Thank You for the help.

Date: 21 May 1995 19:11:01 -0400
From: Dr. Ken
Subject: Re: story problem

You're so close to the answer!  In my opinion, you've done the hard part, 
the part where you really have to figure out what's going on in the problem.
Now you just have to solve an equation, and with more practice, it will be
as easy as pie for you.  

Here's what I would do in your situation: first multiply the entire equation
by 5, so you get x/2 + x/3 = 1.  I just did that to make things a little
simpler, to make the numbers easier.  

Now what do you do when you see two fractions with an addition sign 
between them?  You add them, and to add them you need a common 
denominator.  So the equation becomes 3x/6 + 2x/6 = 1

                 (3x + 2x)/6 = 1
                        5x/6 = 1
                          5x = 6

I bet you can take it from here.  Let us know if you need more help on it!

-K