PSLE Billy had green markers and yellow markers for sale. He sold 140 green markers. 30% of the markers sold were yellow.
- How many green markers and yellow markers did Billy sell altogether?
- He sold 50% of his markers. 60% of the markers left unsold were green. How many yellow markers did Billy have at first?
| |
Green |
Yellow |
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 markers sold = 10 u
Number of yellow markers sold = 3 u
Number of green markers sold
= 10 u - 3 u
= 7 u
7 u = 140
1 u = 140 ÷ 7 = 20
Total number of markers sold
= 10 u
= 10 x 20
= 200
(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 green = 60%
Percent of the markers left unsold that were yellow = 100% - 60% = 40%
Number of the markers left unsold that were yellow
= 40% x 10 u
=
40100 x 10 u
= 4 u
Number of yellow markers that Billy had at first
= 4 u + 3 u
= 7 u
= 7 x 20
= 140
Answer(s): (a) 200; (b) 140
