PSLE
Kimberly had a total of 84 gold and yellow beads. She used 20 gold beads and 75% of the yellow beads. After that, the ratio of the number of gold beads to yellow beads Kimberly had was 4 : 1.

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

	Gold beads	Yellow beads	Total
Before	4 u + 20	4 u	8 u + 20
Change	- 20	- 3 u
After	4 u	1 u	5 u
Comparing gold beads and yellow beads in the end	4	1	5

(a)
75% = ⁷⁵₁₀₀ = ³₄

Fraction of her yellow beads that Kimberly used = ³₄

(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 = 4 u
Number of gold beads at first = 4 u + 20

Total number of beads at first
= 4 u + 4 u + 20
= 8 u + 20

8 u + 20 = 84
8 u = 84 - 20
8 u = 64

1 u = 64 ÷ 8 = 8

Number of yellow beads in the end = 1 u
Number of gold beads in the end = 4 u

Total number of beads in the end
= 4 u + 1 u
= 5 u
= 5 x 8
= 40

Answer(s): (a)³₄; (b) 40