PSLE Caden had red files and blue files for sale. He sold 210 red files. 40% of the files sold were blue.
- How many red files and blue files did Caden sell altogether?
- He sold 50% of his files. 60% of the files left unsold were red. How many blue files did Caden have at first?
|
Red |
Blue |
Total |
Total in percent |
Before |
6 u |
4 u |
10 u |
100% |
Change |
- 60% - 3 u |
- 40% - 2 u |
- 100% - 5 u |
- 50% |
After |
60% 3 u |
40% 2 u |
100% 5 u |
50%
|
40% =
40100 =
25 Total number of files sold = 5 u
Number of blue files sold = 2 u
Number of red files sold
= 5 u - 2 u
= 3 u
3 u = 210
1 u = 210 ÷ 3 = 70
Total number of files sold
= 5 u
= 5 x 70
= 350
(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 red = 60%
Percent of the files left unsold that were blue = 100% - 60% = 40%
Number of the files left unsold that were blue
= 40% x 5 u
=
40100 x 5 u
= 2 u
Number of blue files that Caden had at first
= 2 u + 2 u
= 4 u
= 4 x 70
= 280
Answer(s): (a) 350; (b) 280