PSLE
Zoe had a total of 173 purple and silver beads. She used 38 purple beads and 90% of the silver beads. After that, the ratio of the number of purple beads to silver beads Zoe had was 5 : 1.

1. What fraction of her silver beads did Zoe use? Give your answer in the simplest form.
2. How many beads did Zoe have in the end?

	Purple beads	Silver beads	Total
Before	5 u + 38	10 u	15 u + 38
Change	- 38	- 9 u
After	5 u	1 u	6 u
Comparing purple beads and silver beads in the end	5	1	6

(a)
90% = ⁹⁰₁₀₀ = ⁹₁₀

Fraction of her silver beads that Zoe used = ⁹₁₀

(b)
The number of silver 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 silver beads at first = 10 u
Number of purple beads at first = 5 u + 38

Total number of beads at first
= 10 u + 5 u + 38
= 15 u + 38

15 u + 38 = 173
15 u = 173 - 38
15 u = 135

1 u = 135 ÷ 15 = 9

Number of silver beads in the end = 1 u
Number of purple beads in the end = 5 u

Total number of beads in the end
= 5 u + 1 u
= 6 u
= 6 x 9
= 54

Answer(s): (a)⁹₁₀; (b) 54