PSLE
Linda baked some shortbreads. She gave ¹₈ of the shortbreads to her students and 81 to her friends. She was left with ¹₂ of the shortbreads. She packed these into 14 boxes. Some boxes contained 6 shortbreads while the rest contained 9 shortbreads.

1. How many shortbreads were packed into the 14 boxes?
2. How many boxes contained 9 shortbreads?

(a)
Fraction of the shortbreads given to her friends
= 1 - ¹₈ - ¹₂

= 1 - ¹₈ - ⁴₈
= ³₈

Number of shortbreads that Linda gave to her friends = 3 u

3 u = 81

1 u = 81 ÷ 3 = 27

Number of shortbreads that were packed in 14 boxes
= 4 u
= 4 x 27
= 108

Number of shortbreads that were packed in 14 boxes = 108

Boxes of 9	Shortbreads	Boxes of 6	Shortbreads	Total shortbreads
14	126	0	0	126
13	117	1	6	123

If all the shortbreads are packed in boxes of 9, the number of shortbreads needed
= 14 x 9
= 126

Small difference
= 126 - 123
= 3

Big difference
= 126 - 108
= 18

Number of boxes of 6 shortbreads 
= 18 ÷ 3
= 6

Number of boxes of 9 shortbreads
= 14 - 6
= 8

Answer(s): (a) 108; (b) 8