PSLE
Sabrina had a total of 267 yellow and pink beads. She used 42 yellow beads and 40% of the pink beads. After that, the ratio of the number of yellow beads to pink beads Sabrina had was 10 : 3.

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

	Yellow	Pink	Total
Before	10 u + 42	5 u	15 u + 42
Change	- 42	- 2 u
After	10 u	3 u	13 u
Comparing yellow beads and pink beads in the end	10	3	13

(a)
40% = ⁴⁰₁₀₀ = ²₅

Fraction of her pink beads that Sabrina used = ²₅

Fraction of her pink beads that Sabrina was left with
= 1 - ²₅
= ³₅

(b)
The number of pink 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 pink beads at first = 5 u
Number of yellow beads at first = 10 u + 42

Total number of beads at first
= 5 u + 10 u + 42
= 15 u + 42

15 u + 42 = 267
15 u = 267 - 42
15 u = 225

1 u = 225 ÷ 15 = 15

Number of pink beads in the end = 3 u
Number of yellow beads in the end = 10 u

Number of more yellow beads than pink beads that Sabrina had in the end
= 10 u - 3 u
= 7 u
= 7 x 15
= 105

Answer(s): (a)³₅; (b) 105