PSLE Seth had a total of 774 short and long rulers. After selling an equal number of both types, he had
25 of the short rulers and
16 of the long ones left. What was the total number of rulers sold?
Fraction of the short rulers sold
= 1 -
25 =
35 Fraction of the long rulers sold
= 1 -
16 =
56 The number of short rulers and long rulers sold is the same.
Make the numerators the same.
LCM of 3 and 5 = 15
35 Long rulers =
56 Short rulers
3x55x5 Long rulers =
5x36x3 Short rulers
1525 Long rulers =
1518 Short rulers
|
Long |
Short |
Total |
Before |
25 u |
18 u |
43 u |
Change |
- 15 u |
- 15 u |
- 30 u |
After |
10 u |
3 u |
13 u |
Total number of rulers at first
= 25 u + 18 u
= 43 u
43 u = 774
1 u = 774 ÷ 43 = 18
Total number of rulers sold
= 15 u + 15 u
= 30 u
= 30 x 18
= 540
Answer(s): 540