PSLE Reggie had red pens and orange pens for sale. He sold 90 red pens. 40% of the pens sold were orange.
- How many red pens and orange pens did Reggie sell altogether?
- He sold 50% of his pens. 60% of the pens left unsold were red. How many orange pens did Reggie have at first?
| |
Red |
Orange |
Total |
Total in percent |
| Before |
6 u |
4 u |
10 u |
100% |
| Change |
- 60%
- 3 u |
- 40%
- 2 u |
- 100%
- 5 u |
- 50% |
| After |
60%
3 u |
40%
2 u |
100%
5 u |
50%
|
40% =
40100 =
25 Total number of pens sold = 5 u
Number of orange pens sold = 2 u
Number of red pens sold
= 5 u - 2 u
= 3 u
3 u = 90
1 u = 90 ÷ 3 = 30
Total number of pens sold
= 5 u
= 5 x 30
= 150
(b)
Percent of the pens left unsold = 100% - 50% = 50% 50% of the pens that were sold = 5 u 50% of the pens that were left unsold = 5 u Percent of the pens left unsold that were red = 60%
Percent of the pens left unsold that were orange = 100% - 60% = 40%
Number of the pens left unsold that were orange
= 40% x 5 u
=
40100 x 5 u
= 2 u
Number of orange pens that Reggie had at first
= 2 u + 2 u
= 4 u
= 4 x 30
= 120
Answer(s): (a) 150; (b) 120
