PSLE Fabian had purple pens and gold pens for sale. He sold 210 purple pens. 30% of the pens sold were gold.
- How many purple pens and gold pens did Fabian sell altogether?
- He sold 50% of his pens. 80% of the pens left unsold were purple. How many gold pens did Fabian have at first?
|
Purple |
Gold |
Total |
Total in percent |
Before |
15 u |
5 u |
20 u |
100% |
Change |
- 70% - 7 u |
- 30% - 3 u |
- 100% - 10 u |
- 50% |
After |
80% 8 u |
20% 2 u |
100% 10 u |
50%
|
30% =
30100 =
310 Total number of pens sold = 10 u
Number of gold pens sold = 3 u
Number of purple pens sold
= 10 u - 3 u
= 7 u
7 u = 210
1 u = 210 ÷ 7 = 30
Total number of pens sold
= 10 u
= 10 x 30
= 300
(b)
Percent of the pens left unsold = 100% - 50% = 50% 50% of the pens that were sold = 10 u 50% of the pens that were left unsold = 10 u Percent of the pens left unsold that were purple = 80%
Percent of the pens left unsold that were gold = 100% - 80% = 20%
Number of the pens left unsold that were gold
= 20% x 10 u
=
20100 x 10 u
= 2 u
Number of gold pens that Fabian had at first
= 2 u + 3 u
= 5 u
= 5 x 30
= 150
Answer(s): (a) 300; (b) 150