PSLE Vincent had red staplers and gold staplers for sale. He sold 350 red staplers. 30% of the staplers sold were gold.
- How many red staplers and gold staplers did Vincent sell altogether?
- He sold 50% of his staplers. 80% of the staplers left unsold were red. How many gold staplers did Vincent have at first?
| |
Red |
Gold |
Total |
Total in percent |
| Before |
15 u |
5 u |
20 u |
100% |
| Change |
- 70%
- 7 u |
- 30%
- 3 u |
- 100%
- 10 u |
- 50% |
| After |
80%
8 u |
20%
2 u |
100%
10 u |
50%
|
30% =
30100 =
310 Total number of staplers sold = 10 u
Number of gold staplers sold = 3 u
Number of red staplers sold
= 10 u - 3 u
= 7 u
7 u = 350
1 u = 350 ÷ 7 = 50
Total number of staplers sold
= 10 u
= 10 x 50
= 500
(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 red = 80%
Percent of the staplers left unsold that were gold = 100% - 80% = 20%
Number of the staplers left unsold that were gold
= 20% x 10 u
=
20100 x 10 u
= 2 u
Number of gold staplers that Vincent had at first
= 2 u + 3 u
= 5 u
= 5 x 50
= 250
Answer(s): (a) 500; (b) 250
