PSLE
Zeph had a collection of folders, highlighters and pencils. He had 59 folders. 30% of his collection was highlighters. He had 41 fewer highlighters than pencils.

1. How many highlighters did Zeph have?
2. Zeph gave away some highlighters. His total collection decreased by 20%. What percentage of his collection was highlighters after that?

(a)
30% = ³⁰₁₀₀ = ³₁₀

Number of highlighters = 3 u
Number of pencils = 3 u + 41
Number of folders = 59
Total number of items = 10 u

10 u = 3 u + 3 u + 41 + 59
10 u - 6 u = 100
4 u = 100

1 u = 100 ÷ 4 = 25

Number of highlighters
= 3 u
= 3 x 25
= 75

(b)
Total number of items at first
= 10 u
= 10 x 25
= 250

Total collection in the end in percent
= 100% - 20%
= 80%

Number of items after giving away some highlighters
= 80% x 250
= ⁸⁰₁₀₀ x 250
= 200

Number of pencils and folders
= 10 u - 3 u
= 7 u
= 7 x 25
= 175

Number of highlighters left
= 200 - 175
= 25

Percentage of his collection that was highlighters after that
= ²⁵₂₀₀ x 100%
= 12.5%

Answer(s): (a) 75; (b) 12.5%