Math Word Problems Demystified - A Self Teaching Guide

STRATEGY: Letx¼Mary’s age andxþ 6 ¼Jan’s age. Then the sum of

their ages isxþxþ 6 ¼32.

IMPLEMENTATION: Solve the equation:

xþxþ 6 ¼ 32

2 xþ 6 ¼ 32

2 xþ 6 
 6 ¼ 32 
 6

2 x¼ 26

21 x

21

¼

26

2

x¼ 13 ðMary’s ageÞ

xþ 6 ¼ 13 þ 6 ¼ 19 ðJan’s ageÞ

EVALUATION: Jan is 6 years older than Mary and the sum of their ages is

13 þ 19 ¼32.

EXAMPLE:A father is 34 years old and his son is 12 years old. In how many

years will the father be twice as old as his son?

SOLUTION:

GOAL: You are being asked to find the number of years it will be when the

father is twice as old as his son.

STRATEGY: Let x¼ the number of years. Then the father’s age inx

years will be 34þxyears and the son’s age inxyears will be 12þxyears.

If the father is twice as old as the son in x years, the equation is

2(12þx)¼ 34 þx.

124 LESSON 12 Solving Age Problems