Algebra and Fractions

Date: 08/30/97 at 16:20:56
From: Annie
Subject: Help me!

Please help me with the three questions below.

1) The sum of two-thirds and one-ninth of a number is 28.  
   Find the number N.

2) When two-fifths of the number N is added to one-eighth of 
   a number N, the total is 63.  Find the number.

3) The sum of one-third and one-fourth of a number N is 141.  
   What is this number?

Date: 08/30/97 at 17:42:31
From: Doctor Anthony
Subject: Re: Help me!

>1) The sum of two-thirds and one-ninth of a number is 28.  
>   Find the number N.

Write the information given as an equation and solve it.

   (2/3)N + (1/9)N = 28

            (7/9)N = 28

                      28 x 9
                 N = --------   =  36
                         7

>2) When two-fifths of the number N is added to one-eighth of 
>   a number N, the total is 63.  Find the number.

   (2/5)N + (1/8)N = 63

          (21/40)N = 63

                      63 x 40
                 N = ---------   =  120
                         21

>3) The sum of one-third and one-fourth of a number N is 141.  
>   What is this number?

   (1/3)N + (1/4)N = 141

           (7/12)N = 141

This does not give an integer value for N and I suspect you have 
copied down the question incorrectly, but you can probably work it out 
for yourself now, using the methods that I have shown you above.

-Doctor Anthony,  The Math Forum
 Check out our web site!  http://mathforum.org/dr.math/