PSLE Luke had a total of 272 red and blue pens. After selling an equal number of both types, he had
35 of the red pens and
56 of the blue ones left. What was the total number of pens sold?
Fraction of the red pens sold
= 1 -
35 =
25 Fraction of the blue pens sold
= 1 -
56 =
16 The number of red pens and blue pens sold is the same.
Make the numerators the same.
LCM of 2 and 1 = 2
25 Long pens =
16 Short pens
2x15x1 Long pens =
1x26x2 Short pens
25 Long pens =
212 Short pens
|
Long |
Short |
Total |
Before |
5 u |
12 u |
17 u |
Change |
- 2 u |
- 2 u |
- 4 u |
After |
3 u |
10 u |
13 u |
Total number of pens at first
= 5 u + 12 u
= 17 u
17 u = 272
1 u = 272 ÷ 17 = 16
Total number of pens sold
= 2 u + 2 u
= 4 u
= 4 x 16
= 64
Answer(s): 64