PSLE Charlie had orange staplers and red staplers for sale. He sold 180 orange staplers. 60% of the staplers sold were red.
- How many orange staplers and red staplers did Charlie sell altogether?
- He sold 50% of his staplers. 80% of the staplers left unsold were orange. How many red staplers did Charlie have at first?
| |
Orange |
Red |
Total |
Total in percent |
| Before |
6 u |
4 u |
10 u |
100% |
| Change |
- 40%
- 2 u |
- 60%
- 3 u |
- 100%
- 5 u |
- 50% |
| After |
80%
4 u |
20%
1 u |
100%
5 u |
50%
|
60% =
60100 =
35 Total number of staplers sold = 5 u
Number of red staplers sold = 3 u
Number of orange staplers sold
= 5 u - 3 u
= 2 u
2 u = 180
1 u = 180 ÷ 2 = 90
Total number of staplers sold
= 5 u
= 5 x 90
= 450
(b)
Percent of the staplers left unsold = 100% - 50% = 50% 50% of the staplers that were sold = 5 u 50% of the staplers that were left unsold = 5 u Percent of the staplers left unsold that were orange = 80%
Percent of the staplers left unsold that were red = 100% - 80% = 20%
Number of the staplers left unsold that were red
= 20% x 5 u
=
20100 x 5 u
= 1 u
Number of red staplers that Charlie had at first
= 1 u + 3 u
= 4 u
= 4 x 90
= 360
Answer(s): (a) 450; (b) 360
