PSLE Reggie had silver staplers and gold staplers for sale. He sold 90 silver staplers. 70% of the staplers sold were gold.
- How many silver staplers and gold staplers did Reggie sell altogether?
- He sold 50% of his staplers. 70% of the staplers left unsold were silver. How many gold staplers did Reggie have at first?
| |
Silver |
Gold |
Total |
Total in percent |
| Before |
10 u |
10 u |
20 u |
100% |
| Change |
- 30%
- 3 u |
- 70%
- 7 u |
- 100%
- 10 u |
- 50% |
| After |
70%
7 u |
30%
3 u |
100%
10 u |
50%
|
70% =
70100 =
710 Total number of staplers sold = 10 u
Number of gold staplers sold = 7 u
Number of silver staplers sold
= 10 u - 7 u
= 3 u
3 u = 90
1 u = 90 ÷ 3 = 30
Total number of staplers sold
= 10 u
= 10 x 30
= 300
(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 silver = 70%
Percent of the staplers left unsold that were gold = 100% - 70% = 30%
Number of the staplers left unsold that were gold
= 30% x 10 u
=
30100 x 10 u
= 3 u
Number of gold staplers that Reggie had at first
= 3 u + 7 u
= 10 u
= 10 x 30
= 300
Answer(s): (a) 300; (b) 300
