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