PSLE Harry had a total of 32 long and short rulers. After selling an equal number of both types, he had
12 of the long rulers and
16 of the short ones left. What was the total number of rulers left?
Fraction of the long rulers sold
= 1 -
12 =
12 Fraction of the short rulers sold
= 1 -
16 =
56 The number of long rulers and short rulers sold is the same.
Make the numerators the same.
LCM of 1 and 5 = 5
12 Long rulers =
56 Short rulers
1x52x5 Long rulers =
5x16x1 Short rulers
510 Long rulers =
56 Short rulers
|
Long |
Short |
Total |
Before |
10 u |
6 u |
16 u |
Change |
- 5 u |
- 5 u |
- 10 u |
After |
5 u |
1 u |
6 u |
Total number of rulers at first
= 10 u + 6 u
= 16 u
16 u = 32
1 u = 32 ÷ 16 = 2
Total number of rulers left
= 5 u + 1 u
= 6 u
= 6 x 2
= 12
Answer(s): 12