PSLE Oliver had a total of 190 blue and red pens. After selling an equal number of both types, he had
14 of the blue pens and
12 of the red ones left. What was the total number of pens left?
Fraction of the blue pens sold
= 1 -
14 =
34 Fraction of the red pens sold
= 1 -
12 =
12 The number of blue pens and red pens sold is the same.
Make the numerators the same.
LCM of 3 and 1 = 3
34 Long pens =
12 Short pens
3x14x1 Long pens =
1x32x3 Short pens
34 Long pens =
36 Short pens
|
Long |
Short |
Total |
Before |
4 u |
6 u |
10 u |
Change |
- 3 u |
- 3 u |
- 6 u |
After |
1 u |
3 u |
4 u |
Total number of pens at first
= 4 u + 6 u
= 10 u
10 u = 190
1 u = 190 ÷ 10 = 19
Total number of pens left
= 1 u + 3 u
= 4 u
= 4 x 19
= 76
Answer(s): 76