PSLE Charlie had blue staplers and orange staplers for sale. He sold 220 blue staplers. 60% of the staplers sold were orange.
- How many blue staplers and orange staplers did Charlie sell altogether?
- He sold 50% of his staplers. 70% of the staplers left unsold were blue. How many orange staplers did Charlie have at first?
|
Blue |
Orange |
Total |
Total in percent |
Before |
5.5 u |
4.5 u |
10 u |
100% |
Change |
- 40% - 2 u |
- 60% - 3 u |
- 100% - 5 u |
- 50% |
After |
70% 3.5 u |
30% 1.5 u |
100% 5 u |
50%
|
60% =
60100 =
35 Total number of staplers sold = 5 u
Number of orange staplers sold = 3 u
Number of blue staplers sold
= 5 u - 3 u
= 2 u
2 u = 220
1 u = 220 ÷ 2 = 110
Total number of staplers sold
= 5 u
= 5 x 110
= 550
(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 blue = 70%
Percent of the staplers left unsold that were orange = 100% - 70% = 30%
Number of the staplers left unsold that were orange
= 30% x 5 u
=
30100 x 5 u
= 1.5 u
Number of orange staplers that Charlie had at first
= 1.5 u + 3 u
= 4.5 u
= 4.5 x 110
= 495
Answer(s): (a) 550; (b) 495