PSLE Ben had green files and purple files for sale. He sold 330 green files. 40% of the files sold were purple.
- How many green files and purple files did Ben sell altogether?
- He sold 50% of his files. 80% of the files left unsold were green. How many purple files did Ben have at first?
|
Green |
Purple |
Total |
Total in percent |
Before |
7 u |
3 u |
10 u |
100% |
Change |
- 60% - 3 u |
- 40% - 2 u |
- 100% - 5 u |
- 50% |
After |
80% 4 u |
20% 1 u |
100% 5 u |
50%
|
40% =
40100 =
25 Total number of files sold = 5 u
Number of purple files sold = 2 u
Number of green files sold
= 5 u - 2 u
= 3 u
3 u = 330
1 u = 330 ÷ 3 = 110
Total number of files sold
= 5 u
= 5 x 110
= 550
(b)
Percent of the files left unsold = 100% - 50% = 50% 50% of the files that were sold = 5 u 50% of the files that were left unsold = 5 u Percent of the files left unsold that were green = 80%
Percent of the files left unsold that were purple = 100% - 80% = 20%
Number of the files left unsold that were purple
= 20% x 5 u
=
20100 x 5 u
= 1 u
Number of purple files that Ben had at first
= 1 u + 2 u
= 3 u
= 3 x 110
= 330
Answer(s): (a) 550; (b) 330