PSLE
Sabrina had a total of 266 purple and yellow beads. She used 11 purple beads and 70% of the yellow beads. After that, the ratio of the number of purple beads to yellow beads Sabrina had was 5 : 3.

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

	Purple	Yellow	Total
Before	5 u + 11	10 u	15 u + 11
Change	- 11	- 7 u
After	5 u	3 u	8 u
Comparing purple beads and yellow beads in the end	5	3	8

(a)
70% = ⁷⁰₁₀₀ = ⁷₁₀

Fraction of her yellow beads that Sabrina used = ⁷₁₀

Fraction of her yellow beads that Sabrina was left with
= 1 - ⁷₁₀
= ³₁₀

(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 = 10 u
Number of purple beads at first = 5 u + 11

Total number of beads at first
= 10 u + 5 u + 11
= 15 u + 11

15 u + 11 = 266
15 u = 266 - 11
15 u = 255

1 u = 255 ÷ 15 = 17

Number of yellow beads in the end = 3 u
Number of purple beads in the end = 5 u

Number of more purple beads than yellow beads that Sabrina had in the end
= 5 u - 3 u
= 2 u
= 2 x 17
= 34

Answer(s): (a)³₁₀; (b) 34