PSLE Archie had a total of 154 blue and red pens. After selling an equal number of both types, he had
56 of the blue pens and
14 of the red ones left. What was the total number of pens sold?
Fraction of the blue pens sold
= 1 -
56 =
16 Fraction of the red pens sold
= 1 -
14 =
34 The number of blue pens and red pens sold is the same.
Make the numerators the same.
LCM of 1 and 3 = 3
16 Long pens =
34 Short pens
1x36x3 Long pens =
3x14x1 Short pens
318 Long pens =
34 Short pens
|
Long |
Short |
Total |
Before |
18 u |
4 u |
22 u |
Change |
- 3 u |
- 3 u |
- 6 u |
After |
15 u |
1 u |
16 u |
Total number of pens at first
= 18 u + 4 u
= 22 u
22 u = 154
1 u = 154 ÷ 22 = 7
Total number of pens sold
= 3 u + 3 u
= 6 u
= 6 x 7
= 42
Answer(s): 42