PSLE
Julie had a total of 71 blue and black beads. She used 41 blue beads and 25% of the black beads. After that, the ratio of the number of blue beads to black beads Julie had was 2 : 3.

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

	Blue beads	Black beads	Total
Before	2 u + 41	4 u	6 u + 41
Change	- 41	- 1 u
After	2 u	3 u	5 u
Comparing blue beads and black beads in the end	2	3	5

(a)
25% = ²⁵₁₀₀ = ¹₄

Fraction of her black beads that Julie used = ¹₄

(b)
The number of black 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 black beads at first = 4 u
Number of blue beads at first = 2 u + 41

Total number of beads at first
= 4 u + 2 u + 41
= 6 u + 41

6 u + 41 = 71
6 u = 71 - 41
6 u = 30

1 u = 30 ÷ 6 = 5

Number of black beads in the end = 3 u
Number of blue beads in the end = 2 u

Total number of beads in the end
= 2 u + 3 u
= 5 u
= 5 x 5
= 25

Answer(s): (a)¹₄; (b) 25