PSLE Henry had a total of 69 red and blue pens. After selling an equal number of both types, he had
14 of the red pens and
35 of the blue ones left. What was the total number of pens sold?
Fraction of the red pens sold
= 1 -
14 =
34 Fraction of the blue pens sold
= 1 -
35 =
25 The number of red pens and blue pens sold is the same.
Make the numerators the same.
LCM of 3 and 2 = 6
34 Long pens =
25 Short pens
3x24x2 Long pens =
2x35x3 Short pens
68 Long pens =
615 Short pens
|
Long |
Short |
Total |
Before |
8 u |
15 u |
23 u |
Change |
- 6 u |
- 6 u |
- 12 u |
After |
2 u |
9 u |
11 u |
Total number of pens at first
= 8 u + 15 u
= 23 u
23 u = 69
1 u = 69 ÷ 23 = 3
Total number of pens sold
= 6 u + 6 u
= 12 u
= 12 x 3
= 36
Answer(s): 36