PSLE
Japheth had gold staplers and purple staplers for sale. He sold 210 gold staplers. 40% of the staplers sold were purple.

1. How many gold staplers and purple staplers did Japheth sell altogether?
2. He sold 50% of his staplers. 75% of the staplers left unsold were gold. How many purple staplers did Japheth have at first?

	Gold	Purple	Total	Total in percent
Before	6.75 u	3.25 u	10 u	100%
Change	- 60% - 3 u	- 40% - 2 u	- 100% - 5 u	- 50%
After	75% 3.75 u	25% 1.25 u	100% 5 u	50%

40% = ⁴⁰₁₀₀ = ²₅

Total number of staplers sold = 5 u
Number of purple staplers sold = 2 u

Number of gold staplers sold
= 5 u - 2 u
= 3 u

3 u = 210

1 u = 210 ÷ 3 = 70

Total number of staplers sold
= 5 u
= 5 x 70
= 350

(b)
Percent of the staplers left unsold
= 100% - 50%
= 50%

50% of the staplers that were sold = 5 u
50% of the staplers that were left unsold = 5 u

Percent of the staplers left unsold that were gold = 75%
Percent of the staplers left unsold that were purple = 100% - 75% = 25%

Number of the staplers left unsold that were purple
= 25% x 5 u
= ²⁵₁₀₀ x 5 u
= 1.25 u

Number of purple staplers that Japheth had at first
= 1.25 u + 2 u
= 3.25 u
= 3.25 x 70
= 227.5

Answer(s): (a) 350; (b) 227.5