PSLE John had a total of 432 short and long erasers. After selling an equal number of both types, he had
16 of the short erasers and
56 of the long ones left. What was the total number of erasers sold?
Fraction of the short erasers sold
= 1 -
16 =
56 Fraction of the long erasers sold
= 1 -
56 =
16 The number of short erasers and long erasers sold is the same.
Make the numerators the same.
LCM of 5 and 1 = 5
56 Long erasers =
16 Short erasers
5x16x1 Long erasers =
1x56x5 Short erasers
56 Long erasers =
530 Short erasers
|
Long |
Short |
Total |
Before |
6 u |
30 u |
36 u |
Change |
- 5 u |
- 5 u |
- 10 u |
After |
1 u |
25 u |
26 u |
Total number of erasers at first
= 6 u + 30 u
= 36 u
36 u = 432
1 u = 432 ÷ 36 = 12
Total number of erasers sold
= 5 u + 5 u
= 10 u
= 10 x 12
= 120
Answer(s): 120