PSLE Valen had gold pencils and purple pencils for sale. He sold 350 gold pencils. 30% of the pencils sold were purple.
- How many gold pencils and purple pencils did Valen sell altogether?
- He sold 50% of his pencils. 60% of the pencils left unsold were gold. How many purple pencils did Valen have at first?
| |
Gold |
Purple |
Total |
Total in percent |
| Before |
13 u |
7 u |
20 u |
100% |
| Change |
- 70%
- 7 u |
- 30%
- 3 u |
- 100%
- 10 u |
- 50% |
| After |
60%
6 u |
40%
4 u |
100%
10 u |
50%
|
30% =
30100 =
310 Total number of pencils sold = 10 u
Number of purple pencils sold = 3 u
Number of gold pencils sold
= 10 u - 3 u
= 7 u
7 u = 350
1 u = 350 ÷ 7 = 50
Total number of pencils sold
= 10 u
= 10 x 50
= 500
(b)
Percent of the pencils left unsold = 100% - 50% = 50% 50% of the pencils that were sold = 10 u 50% of the pencils that were left unsold = 10 u Percent of the pencils left unsold that were gold = 60%
Percent of the pencils left unsold that were purple = 100% - 60% = 40%
Number of the pencils left unsold that were purple
= 40% x 10 u
=
40100 x 10 u
= 4 u
Number of purple pencils that Valen had at first
= 4 u + 3 u
= 7 u
= 7 x 50
= 350
Answer(s): (a) 500; (b) 350
