PSLE Daniel had a total of 90 long and short rulers. After selling an equal number of both types, he had
35 of the long rulers and
12 of the short ones left. What was the total number of rulers sold?
Fraction of the long rulers sold
= 1 -
35 =
25 Fraction of the short rulers sold
= 1 -
12 =
12 The number of long rulers and short rulers sold is the same.
Make the numerators the same.
LCM of 2 and 1 = 2
25 Long rulers =
12 Short rulers
2x15x1 Long rulers =
1x22x2 Short rulers
25 Long rulers =
24 Short rulers
|
Long |
Short |
Total |
Before |
5 u |
4 u |
9 u |
Change |
- 2 u |
- 2 u |
- 4 u |
After |
3 u |
2 u |
5 u |
Total number of rulers at first
= 5 u + 4 u
= 9 u
9 u = 90
1 u = 90 ÷ 9 = 10
Total number of rulers sold
= 2 u + 2 u
= 4 u
= 4 x 10
= 40
Answer(s): 40