PSLE
Nora had a total of 131 gold and green beads. She used 47 gold beads and 50% of the green beads. After that, the ratio of the number of gold beads to green beads Nora had was 10 : 1.

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

	Gold	Green	Total
Before	10 u + 47	2 u	12 u + 47
Change	- 47	- 1 u
After	10 u	1 u	11 u
Comparing gold beads and green beads in the end	10	1	11

(a)
50% = ⁵⁰₁₀₀ = ¹₂

Fraction of her green beads that Nora used = ¹₂

Fraction of her green beads that Nora was left with
= 1 - ¹₂
= ¹₂

(b)
The number of green 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 green beads at first = 2 u
Number of gold beads at first = 10 u + 47

Total number of beads at first
= 2 u + 10 u + 47
= 12 u + 47

12 u + 47 = 131
12 u = 131 - 47
12 u = 84

1 u = 84 ÷ 12 = 7

Number of green beads in the end = 1 u
Number of gold beads in the end = 10 u

Number of more gold beads than green beads that Nora had in the end
= 10 u - 1 u
= 9 u
= 9 x 7
= 63

Answer(s): (a)¹₂; (b) 63