PSLE
Xylia baked some biscuits. She gave ¹₆ of the biscuits to her relatives and 76 to her friends. She was left with ¹₂ of the biscuits. She packed these into 16 boxes. Some boxes contained 4 biscuits while the rest contained 9 biscuits.

1. How many biscuits were packed into the 16 boxes?
2. How many boxes contained 9 biscuits?

(a)
Fraction of the biscuits given to her friends
= 1 - ¹₆ - ¹₂

= 1 - ¹₆ - ³₆
= ²₆

Number of biscuits that Xylia gave to her friends = 2 u

2 u = 76

1 u = 76 ÷ 2 = 38

Number of biscuits that were packed in 16 boxes
= 3 u
= 3 x 38
= 114

Number of biscuits that were packed in 16 boxes = 114

Boxes of 9	Biscuits	Boxes of 4	Biscuits	Total biscuits
16	144	0	0	144
15	135	1	4	139

If all the biscuits are packed in boxes of 9, the number of biscuits needed
= 16 x 9
= 144

Small difference
= 144 - 139
= 5

Big difference
= 144 - 114
= 30

Number of boxes of 4 biscuits 
= 30 ÷ 5
= 6

Number of boxes of 9 biscuits
= 16 - 6
= 10

Answer(s): (a) 114; (b) 10