Math Word Problems Demystified - A Self Teaching Guide

EXAMPLE:A person bought ten greeting cards consisting of birthday cards
costing $1.50 each and anniversary cards costing $2.00 each. If the total cost
of the cards was $17.00, find the number of each kind of card the person
bought.

SOLUTION:

GOAL: You are being asked to find how many birthday cards and how many
anniversary cards the person bought.

STRATEGY: Let x¼the number of birthday cards and (10
x)¼the
number of anniversary cards. Since the birthday cards cost $1.50 each,
the value of the birthday cards is 1.5x, and since the anniversary cards cost
$2.00 each, the value of the anniversary cards is 2(10
x). The equation
is 1.5xþ2(10
x)¼17.

IMPLEMENTATION: Solve the equation:

1 : 5 xþ 2 ð 10 
xÞ¼ 17

1 : 5 xþ 20 
 2 x¼ 17

20 
 0 : 5 x¼ 17

20 
 20 
 0 : 5 x¼ 17 
 20

 0 : 5 x¼
 3

 0 : 51 x


 0 : 51

¼

3

0 : 5

x¼6 (birthday cards)

ð 10 
xÞ¼ 10 
 6 ¼4 (anniversary cards)

The person bought 6 birthday cards and 4 anniversary cards.

EVALUATION: 6 birthday cards and 4 anniversary cards cost
6 $1.50þ 4 $2.00¼$9.00þ$8.00¼$17.00.

LESSON 11 Solving Coin Problems 111