PSLE Simon had green pens and gold pens for sale. He sold 180 green pens. 60% of the pens sold were gold.
- How many green pens and gold pens did Simon sell altogether?
- He sold 50% of his pens. 60% of the pens left unsold were green. How many gold pens did Simon have at first?
| |
Green |
Gold |
Total |
Total in percent |
| Before |
5 u |
5 u |
10 u |
100% |
| Change |
- 40%
- 2 u |
- 60%
- 3 u |
- 100%
- 5 u |
- 50% |
| After |
60%
3 u |
40%
2 u |
100%
5 u |
50%
|
60% =
60100 =
35 Total number of pens sold = 5 u
Number of gold pens sold = 3 u
Number of green pens sold
= 5 u - 3 u
= 2 u
2 u = 180
1 u = 180 ÷ 2 = 90
Total number of pens sold
= 5 u
= 5 x 90
= 450
(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 green = 60%
Percent of the pens left unsold that were gold = 100% - 60% = 40%
Number of the pens left unsold that were gold
= 40% x 5 u
=
40100 x 5 u
= 2 u
Number of gold pens that Simon had at first
= 2 u + 3 u
= 5 u
= 5 x 90
= 450
Answer(s): (a) 450; (b) 450
