PSLE
Brandon had green staplers and pink staplers for sale. He sold 240 green staplers. 70% of the staplers sold were pink.

1. How many green staplers and pink staplers did Brandon sell altogether?
2. He sold 50% of his staplers. 60% of the staplers left unsold were green. How many pink staplers did Brandon have at first?

	Green	Pink	Total	Total in percent
Before	9 u	11 u	20 u	100%
Change	- 30% - 3 u	- 70% - 7 u	- 100% - 10 u	- 50%
After	60% 6 u	40% 4 u	100% 10 u	50%

70% = ⁷⁰₁₀₀ = ⁷₁₀

Total number of staplers sold = 10 u
Number of pink staplers sold = 7 u

Number of green staplers sold
= 10 u - 7 u
= 3 u

3 u = 240

1 u = 240 ÷ 3 = 80

Total number of staplers sold
= 10 u
= 10 x 80
= 800

(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 green = 60%
Percent of the staplers left unsold that were pink = 100% - 60% = 40%

Number of the staplers left unsold that were pink
= 40% x 10 u
= ⁴⁰₁₀₀ x 10 u
= 4 u

Number of pink staplers that Brandon had at first
= 4 u + 7 u
= 11 u
= 11 x 80
= 880

Answer(s): (a) 800; (b) 880