PSLE
Ahmad had pink staplers and yellow staplers for sale. He sold 700 pink staplers. 30% of the staplers sold were yellow.

1. How many pink staplers and yellow staplers did Ahmad sell altogether?
2. He sold 50% of his staplers. 70% of the staplers left unsold were pink. How many yellow staplers did Ahmad have at first?

	Pink	Yellow	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 staplers sold = 10 u
Number of yellow staplers sold = 3 u

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

7 u = 700

1 u = 700 ÷ 7 = 100

Total number of staplers sold
= 10 u
= 10 x 100
= 1000

(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 pink = 70%
Percent of the staplers left unsold that were yellow = 100% - 70% = 30%

Number of the staplers left unsold that were yellow
= 30% x 10 u
= ³⁰₁₀₀ x 10 u
= 3 u

Number of yellow staplers that Ahmad had at first
= 3 u + 3 u
= 6 u
= 6 x 100
= 600

Answer(s): (a) 1000; (b) 600