PSLE Vaidev had yellow pencils and silver pencils for sale. He sold 330 yellow pencils. 40% of the pencils sold were silver.
- How many yellow pencils and silver pencils did Vaidev sell altogether?
- He sold 50% of his pencils. 60% of the pencils left unsold were yellow. How many silver pencils did Vaidev have at first?
| |
Yellow |
Silver |
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 silver pencils sold = 2 u
Number of yellow pencils sold
= 5 u - 2 u
= 3 u
3 u = 330
1 u = 330 ÷ 3 = 110
Total number of pencils sold
= 5 u
= 5 x 110
= 550
(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 yellow = 60%
Percent of the pencils left unsold that were silver = 100% - 60% = 40%
Number of the pencils left unsold that were silver
= 40% x 5 u
=
40100 x 5 u
= 2 u
Number of silver pencils that Vaidev had at first
= 2 u + 2 u
= 4 u
= 4 x 110
= 440
Answer(s): (a) 550; (b) 440
