PSLE Oscar had silver staplers and gold staplers for sale. He sold 210 silver staplers. 30% of the staplers sold were gold.
- How many silver staplers and gold staplers did Oscar sell altogether?
- He sold 50% of his staplers. 60% of the staplers left unsold were silver. How many gold staplers did Oscar have at first?
|
Silver |
Gold |
Total |
Total in percent |
Before |
13 u |
7 u |
20 u |
100% |
Change |
- 70% - 7 u |
- 30% - 3 u |
- 100% - 10 u |
- 50% |
After |
60% 6 u |
40% 4 u |
100% 10 u |
50%
|
30% =
30100 =
310 Total number of staplers sold = 10 u
Number of gold staplers sold = 3 u
Number of silver staplers sold
= 10 u - 3 u
= 7 u
7 u = 210
1 u = 210 ÷ 7 = 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 = 60%
Percent of the staplers left unsold that were gold = 100% - 60% = 40%
Number of the staplers left unsold that were gold
= 40% x 10 u
=
40100 x 10 u
= 4 u
Number of gold staplers that Oscar had at first
= 4 u + 3 u
= 7 u
= 7 x 30
= 210
Answer(s): (a) 300; (b) 210