PSLE Perry had a collection of highlighters, punchers and pencils. He had 106 highlighters. 30% of his collection was punchers. He had 14 fewer punchers than pencils.
- How many punchers did Perry have?
- Perry gave away some punchers. His total collection decreased by 20%. What percentage of his collection was punchers after that?
(a)
30% =
30100 =
310 Number of punchers = 3 u
Number of pencils = 3 u + 14
Number of highlighters = 106
Total number of items = 10 u
10 u = 3 u + 3 u + 14 + 106
10 u - 6 u = 120
4 u = 120
1 u = 120 ÷ 4 = 30
Number of punchers
= 3 u
= 3 x 30
= 90
(b)
Total number of items at first
= 10 u
= 10 x 30
= 300
Total collection in the end in percent
= 100% - 20%
= 80%
Number of items after giving away some punchers
= 80% x 300
=
80100 x 300
= 240
Number of pencils and highlighters
= 10 u - 3 u
= 7 u
= 7 x 30
= 210
Number of punchers left
= 240 - 210
= 30
Percentage of his collection that was punchers after that
=
30240 x 100%
= 12.5%
Answer(s): (a) 90; (b) 12.5%