PSLE Glen had yellow staplers and red staplers for sale. He sold 180 yellow staplers. 70% of the staplers sold were red.
- How many yellow staplers and red staplers did Glen sell altogether?
- He sold 50% of his staplers. 75% of the staplers left unsold were yellow. How many red staplers did Glen have at first?
| |
Yellow |
Red |
Total |
Total in percent |
| Before |
10.5 u |
9.5 u |
20 u |
100% |
| Change |
- 30%
- 3 u |
- 70%
- 7 u |
- 100%
- 10 u |
- 50% |
| After |
75%
7.5 u |
25%
2.5 u |
100%
10 u |
50%
|
70% =
70100 =
710 Total number of staplers sold = 10 u
Number of red staplers sold = 7 u
Number of yellow staplers sold
= 10 u - 7 u
= 3 u
3 u = 180
1 u = 180 ÷ 3 = 60
Total number of staplers sold
= 10 u
= 10 x 60
= 600
(b)
Percent of the staplers left unsold = 100% - 50% = 50% 50% of the staplers that were sold = 10 u 50% of the staplers that were left unsold = 10 u Percent of the staplers left unsold that were yellow = 75%
Percent of the staplers left unsold that were red = 100% - 75% = 25%
Number of the staplers left unsold that were red
= 25% x 10 u
=
25100 x 10 u
= 2.5 u
Number of red staplers that Glen had at first
= 2.5 u + 7 u
= 9.5 u
= 9.5 x 60
= 570
Answer(s): (a) 600; (b) 570
