Math Word Problems Demystified - A Self Teaching Guide

8. If the sum of three consecutive numbers is 39, find the numbers.


9. If the sum of two consecutive odd numbers is 48, find the numbers.


10. Find two numbers whose sum is 30 and whose difference is 6.

SOLUTIONS:

1. Letx¼the number; then

3 xþ 3 ¼ 30

3 xþ 3 
 3 ¼ 30 
 3

3 x¼ 27

31 x

31

¼

27

3

x¼ 9

2. Let x¼length of first piece; xþ 7 ¼length of second piece;
   xþ 14 ¼length of third piece; then

xþxþ 7 þxþ 14 ¼ 51

3 xþ 21 ¼ 51

3 xþ 21 
 21 ¼ 51 
 21

3 x¼ 30

31 x

31

¼

30

3

x¼10 inches (first piece)

xþ 7 ¼ 10 þ 7 ¼17 inches (second piece)

xþ 14 ¼ 10 þ 14 ¼24 inches (third piece)

94 LESSON 9 Solving Number Problems