PSLE
Risa had a total of 202 purple and yellow beads. She used 48 purple beads and 80% of the yellow beads. After that, the ratio of the number of purple beads to yellow beads Risa had was 9 : 1.

1. What fraction of her yellow beads was Risa left with? Give your answer in the simplest form.
2. How many more purple beads than yellow beads did Risa have in the end?

	Purple	Yellow	Total
Before	9 u + 48	5 u	14 u + 48
Change	- 48	- 4 u
After	9 u	1 u	10 u
Comparing purple beads and yellow beads in the end	9	1	10

(a)
80% = ⁸⁰₁₀₀ = ⁴₅

Fraction of her yellow beads that Risa used = ⁴₅

Fraction of her yellow beads that Risa was left with
= 1 - ⁴₅
= ¹₅

(b)
The number of yellow beads in the end is repeated.
Since the numbers are already the same, we do not need to use LCM to make them the same.

Number of yellow beads at first = 5 u
Number of purple beads at first = 9 u + 48

Total number of beads at first
= 5 u + 9 u + 48
= 14 u + 48

14 u + 48 = 202
14 u = 202 - 48
14 u = 154

1 u = 154 ÷ 14 = 11

Number of yellow beads in the end = 1 u
Number of purple beads in the end = 9 u

Number of more purple beads than yellow beads that Risa had in the end
= 9 u - 1 u
= 8 u
= 8 x 11
= 88

Answer(s): (a)¹₅; (b) 88