PSLE Riordan had blue files and gold files for sale. He sold 220 blue files. 60% of the files sold were gold.
- How many blue files and gold files did Riordan sell altogether?
- He sold 50% of his files. 75% of the files left unsold were blue. How many gold files did Riordan have at first?
| |
Blue |
Gold |
Total |
Total in percent |
| Before |
5.75 u |
4.25 u |
10 u |
100% |
| Change |
- 40%
- 2 u |
- 60%
- 3 u |
- 100%
- 5 u |
- 50% |
| After |
75%
3.75 u |
25%
1.25 u |
100%
5 u |
50%
|
60% =
60100 =
35 Total number of files sold = 5 u
Number of gold files sold = 3 u
Number of blue files sold
= 5 u - 3 u
= 2 u
2 u = 220
1 u = 220 ÷ 2 = 110
Total number of files sold
= 5 u
= 5 x 110
= 550
(b)
Percent of the files left unsold = 100% - 50% = 50% 50% of the files that were sold = 5 u 50% of the files that were left unsold = 5 u Percent of the files left unsold that were blue = 75%
Percent of the files left unsold that were gold = 100% - 75% = 25%
Number of the files left unsold that were gold
= 25% x 5 u
=
25100 x 5 u
= 1.25 u
Number of gold files that Riordan had at first
= 1.25 u + 3 u
= 4.25 u
= 4.25 x 110
= 467.5
Answer(s): (a) 550; (b) 467.5
