PSLE
A box contained pink and orange beads. At first, the number of pink beads was ¹₅ the number of orange beads. After ²₃ of the pink beads and ⁵₆ of the orange beads were used, 63 beads were left.

1. What fraction of the beads were left? Leave your answer in the simplest form.
2. How many beads were used?

	Pink	Orange
Comparing pink beads and orange beads at first	1x6 = 6 u	5x6 = 30 u
Before	3x2 = 6 u	6x5 = 30 u
Change	- 2x2 =  - 4 u	- 5x5 = - 25 u
After	1x2 =  2 u	1x5 = 5 u

(a)
The number of orange beads at first is repeated. Make the number of orange beads at first the same. 
LCM of 5 and 6 is 30.

The number of pink beads at first is repeated.

Since the number of pink beads at first is 6 u, we make the total number of pink beads at first the same by multiplying 3 by 2 to become 6 u too.

Fraction of the beads left
= ^{2 + 5}_{6 + 30} 
= ⁷₃₆

(b)
Number of beads left
= 2 u + 5 u
= 7 u

7 u = 63

1 u = 63 ÷ 7 = 9

Number of beads used
= 4 u + 25 u
= 29 u
= 29 x 9
= 261

Answer(s): (a) ⁷₃₆; (b) 261