PSLE Jeremy had green pencils and purple pencils for sale. He sold 140 green pencils. 30% of the pencils sold were purple.
- How many green pencils and purple pencils did Jeremy sell altogether?
- He sold 50% of his pencils. 70% of the pencils left unsold were green. How many purple pencils did Jeremy have at first?
|
Green |
Purple |
Total |
Total in percent |
Before |
14 u |
6 u |
20 u |
100% |
Change |
- 70% - 7 u |
- 30% - 3 u |
- 100% - 10 u |
- 50% |
After |
70% 7 u |
30% 3 u |
100% 10 u |
50%
|
30% =
30100 =
310 Total number of pencils sold = 10 u
Number of purple pencils sold = 3 u
Number of green pencils sold
= 10 u - 3 u
= 7 u
7 u = 140
1 u = 140 ÷ 7 = 20
Total number of pencils sold
= 10 u
= 10 x 20
= 200
(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 green = 70%
Percent of the pencils left unsold that were purple = 100% - 70% = 30%
Number of the pencils left unsold that were purple
= 30% x 10 u
=
30100 x 10 u
= 3 u
Number of purple pencils that Jeremy had at first
= 3 u + 3 u
= 6 u
= 6 x 20
= 120
Answer(s): (a) 200; (b) 120