PSLE
Fiona had a total of 267 orange and silver beads. She used 11 orange beads and 90% of the silver beads. After that, the ratio of the number of orange beads to silver beads Fiona had was 6 : 1.

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

	Orange	Silver	Total
Before	6 u + 11	10 u	16 u + 11
Change	- 11	- 9 u
After	6 u	1 u	7 u
Comparing orange beads and silver beads in the end	6	1	7

(a)
90% = ⁹⁰₁₀₀ = ⁹₁₀

Fraction of her silver beads that Fiona used = ⁹₁₀

Fraction of her silver beads that Fiona was left with
= 1 - ⁹₁₀
= ¹₁₀

(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 orange beads at first = 6 u + 11

Total number of beads at first
= 10 u + 6 u + 11
= 16 u + 11

16 u + 11 = 267
16 u = 267 - 11
16 u = 256

1 u = 256 ÷ 16 = 16

Number of silver beads in the end = 1 u
Number of orange beads in the end = 6 u

Number of more orange beads than silver beads that Fiona had in the end
= 6 u - 1 u
= 5 u
= 5 x 16
= 80

Answer(s): (a)¹₁₀; (b) 80