PSLE
Diana baked some biscuits. She gave ¹₆ of the biscuits to her students and 52 to her friends. She was left with ¹₂ of the biscuits. She packed these into 15 boxes. Some boxes contained 4 biscuits while the rest contained 6 biscuits.

1. How many biscuits were packed into the 15 boxes?
2. How many boxes contained 6 biscuits?

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

= 1 - ¹₆ - ³₆
= ²₆

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

2 u = 52

1 u = 52 ÷ 2 = 26

Number of biscuits that were packed in 15 boxes
= 3 u
= 3 x 26
= 78

Number of biscuits that were packed in 15 boxes = 78

Boxes of 6	Biscuits	Boxes of 4	Biscuits	Total biscuits
15	90	0	0	90
14	84	1	4	88

If all the biscuits are packed in boxes of 6, the number of biscuits needed
= 15 x 6
= 90

Small difference
= 90 - 88
= 2

Big difference
= 90 - 78
= 12

Number of boxes of 4 biscuits 
= 12 ÷ 2
= 6

Number of boxes of 6 biscuits
= 15 - 6
= 9

Answer(s): (a) 78; (b) 9