PSLE
Eva had a total of 108 gold and silver beads. She used 12 gold beads and 80% of the silver beads. After that, the ratio of the number of gold beads to silver beads Eva had was 7 : 1.

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

	Gold beads	Silver beads	Total
Before	7 u + 12	5 u	12 u + 12
Change	- 12	- 4 u
After	7 u	1 u	8 u
Comparing gold beads and silver beads in the end	7	1	8

(a)
80% = ⁸⁰₁₀₀ = ⁴₅

Fraction of her silver beads that Eva used = ⁴₅

(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 = 5 u
Number of gold beads at first = 7 u + 12

Total number of beads at first
= 5 u + 7 u + 12
= 12 u + 12

12 u + 12 = 108
12 u = 108 - 12
12 u = 96

1 u = 96 ÷ 12 = 8

Number of silver beads in the end = 1 u
Number of gold beads in the end = 7 u

Total number of beads in the end
= 7 u + 1 u
= 8 u
= 8 x 8
= 64

Answer(s): (a)⁴₅; (b) 64