PSLE Glen had a total of 155 short and long erasers. After selling an equal number of both types, he had
45 of the short erasers and
16 of the long ones left. What was the total number of erasers sold?
Fraction of the short erasers sold
= 1 -
45 =
15 Fraction of the long erasers sold
= 1 -
16 =
56 The number of short erasers and long erasers sold is the same.
Make the numerators the same.
LCM of 1 and 5 = 5
15 Long erasers =
56 Short erasers
1x55x5 Long erasers =
5x16x1 Short erasers
525 Long erasers =
56 Short erasers
|
Long |
Short |
Total |
Before |
25 u |
6 u |
31 u |
Change |
- 5 u |
- 5 u |
- 10 u |
After |
20 u |
1 u |
21 u |
Total number of erasers at first
= 25 u + 6 u
= 31 u
31 u = 155
1 u = 155 ÷ 31 = 5
Total number of erasers sold
= 5 u + 5 u
= 10 u
= 10 x 5
= 50
Answer(s): 50