PSLE
Ryan had yellow markers and orange markers for sale. He sold 160 yellow markers. 60% of the markers sold were orange.

1. How many yellow markers and orange markers did Ryan sell altogether?
2. He sold 50% of his markers. 75% of the markers left unsold were yellow. How many orange markers did Ryan have at first?

	Yellow	Orange	Total	Total in percent
Before	5.75 u	4.25 u	10 u	100%
Change	- 40% - 2 u	- 60% - 3 u	- 100% - 5 u	- 50%
After	75% 3.75 u	25% 1.25 u	100% 5 u	50%

60% = ⁶⁰₁₀₀ = ³₅

Total number of markers sold = 5 u
Number of orange markers sold = 3 u

Number of yellow markers sold
= 5 u - 3 u
= 2 u

2 u = 160

1 u = 160 ÷ 2 = 80

Total number of markers sold
= 5 u
= 5 x 80
= 400

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

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

Percent of the markers left unsold that were yellow = 75%
Percent of the markers left unsold that were orange = 100% - 75% = 25%

Number of the markers left unsold that were orange
= 25% x 5 u
= ²⁵₁₀₀ x 5 u
= 1.25 u

Number of orange markers that Ryan had at first
= 1.25 u + 3 u
= 4.25 u
= 4.25 x 80
= 340

Answer(s): (a) 400; (b) 340