Math Word Problems Demystified - A Self Teaching Guide

5. A person made 40 small bags of candy, some of which sold for $0.50
   and the rest sold for $0.75 each. If the total amount he made was
   $23.25, find the number of bags of each he sold.

SOLUTIONS:

1. Letx¼the first number
   andy¼the second number

y¼ 4 x

xþy¼ 40

Substitute foryin the second equation and solve forx.

xþ 4 x¼ 40

5 x¼ 40

51 x

51

¼

40

5

x¼ 8

Solve fory:

y¼ 4 x

y¼ 4  8

y¼ 32

2. Letx¼the ten’s digit
   andy¼the one’s digit

10 xþy¼original number

10 yþx¼number with digits reversed

xþy¼ 14

10 xþyþ 18 ¼ 10 yþx

LESSON 18 Using Two Equations 221