PSLE Elijah had a total of 138 long and short rulers. After selling an equal number of both types, he had
25 of the long rulers and
56 of the short ones left. What was the total number of rulers sold?
Fraction of the long rulers sold
= 1 -
25 =
35 Fraction of the short rulers sold
= 1 -
56 =
16 The number of long rulers and short rulers sold is the same.
Make the numerators the same.
LCM of 3 and 1 = 3
35 Long rulers =
16 Short rulers
3x15x1 Long rulers =
1x36x3 Short rulers
35 Long rulers =
318 Short rulers
|
Long |
Short |
Total |
Before |
5 u |
18 u |
23 u |
Change |
- 3 u |
- 3 u |
- 6 u |
After |
2 u |
15 u |
17 u |
Total number of rulers at first
= 5 u + 18 u
= 23 u
23 u = 138
1 u = 138 ÷ 23 = 6
Total number of rulers sold
= 3 u + 3 u
= 6 u
= 6 x 6
= 36
Answer(s): 36