PSLE Jenson had blue pencils and gold pencils for sale. He sold 150 blue pencils. 40% of the pencils sold were gold.
- How many blue pencils and gold pencils did Jenson sell altogether?
- He sold 50% of his pencils. 60% of the pencils left unsold were blue. How many gold pencils did Jenson have at first?
| |
Blue |
Gold |
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 pencils sold = 5 u
Number of gold pencils sold = 2 u
Number of blue pencils sold
= 5 u - 2 u
= 3 u
3 u = 150
1 u = 150 ÷ 3 = 50
Total number of pencils sold
= 5 u
= 5 x 50
= 250
(b)
Percent of the pencils left unsold = 100% - 50% = 50% 50% of the pencils that were sold = 5 u 50% of the pencils that were left unsold = 5 u Percent of the pencils left unsold that were blue = 60%
Percent of the pencils left unsold that were gold = 100% - 60% = 40%
Number of the pencils left unsold that were gold
= 40% x 5 u
=
40100 x 5 u
= 2 u
Number of gold pencils that Jenson had at first
= 2 u + 2 u
= 4 u
= 4 x 50
= 200
Answer(s): (a) 250; (b) 200
