Applied Problems Involving Fractions We will follow the same method from 181A to solve applied problems that involve fractions. Example The width of a piece of paper is 8½ inches.  If you want the left and right margins to be 2/3 inches, what is the width of the written part of the page? Solution We begin by stating our goal: "The width of the written part of the page is          inches" Next draw the picture letting x be the width of the written  We see that the total width of 8½ is made up of the two margins and the written space.  The margins take up                  2            4         2  x          =                            3            3 If we take away the margin width from the paper width, we get the width of the writing, that is                              1         2          x  = 8       -                              2         3                  17         2            =           -                 8 x 2 + 1 =  17                    2         3                  17 x 3         2 x 2            =                 -                      The LCD of 2 and 3 is 6                    2 x 3         3 x 2                  51         4              47               5            =           -             =             =    7            6 x 7 + 5  =  47                   6          6               6                6 We can conclude that  The width of the written part of the page is   7 5/6   inches.   Example You earn 6½ dollars per hour at your job.  For over time work you get 1½ times your wages.  If you work 4 hour of overtime, how much overtime pay will you get? Solution We begin by writing our goal: "I will earn \$        ." Because of the word "times" we see that this is a multiplication problem.  We write                                 1            1             4       13           3            4 x  6         x  1           =          x          x              6 x 2 + 1  =  13                        2            2             1         2           2                1       13           3          39         =          x          x            =                   We cancelled the 4 with the two 2's                1         1           1           1 "I will earn \$  39  ."   Back to the Fractions page Back to the Math 187A page Back to the Math Department page e-mail Questions and Suggestions