PSLE Oliver had a total of 225 long and short erasers. After selling an equal number of both types, he had
35 of the long erasers and
25 of the short ones left. What was the total number of erasers sold?
Fraction of the long erasers sold
= 1 -
35 =
25 Fraction of the short erasers sold
= 1 -
25 =
35 The number of long erasers and short erasers sold is the same.
Make the numerators the same.
LCM of 2 and 3 = 6
25 Long erasers =
35 Short erasers
2x35x3 Long erasers =
3x25x2 Short erasers
615 Long erasers =
610 Short erasers
|
Long |
Short |
Total |
Before |
15 u |
10 u |
25 u |
Change |
- 6 u |
- 6 u |
- 12 u |
After |
9 u |
4 u |
13 u |
Total number of erasers at first
= 15 u + 10 u
= 25 u
25 u = 225
1 u = 225 ÷ 25 = 9
Total number of erasers sold
= 6 u + 6 u
= 12 u
= 12 x 9
= 108
Answer(s): 108