PSLE
Abi baked some shortbreads. She gave ¹₆ of the shortbreads to her relatives and 82 to her friends. She was left with ¹₂ of the shortbreads. She packed these into 13 boxes. Some boxes contained 6 shortbreads while the rest contained 11 shortbreads.

1. How many shortbreads were packed into the 13 boxes?
2. How many boxes contained 11 shortbreads?

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

= 1 - ¹₆ - ³₆
= ²₆

Number of shortbreads that Abi gave to her friends = 2 u

2 u = 82

1 u = 82 ÷ 2 = 41

Number of shortbreads that were packed in 13 boxes
= 3 u
= 3 x 41
= 123

Number of shortbreads that were packed in 13 boxes = 123

Boxes of 11	Shortbreads	Boxes of 6	Shortbreads	Total shortbreads
13	143	0	0	143
12	132	1	6	138

If all the shortbreads are packed in boxes of 11, the number of shortbreads needed
= 13 x 11
= 143

Small difference
= 143 - 138
= 5

Big difference
= 143 - 123
= 20

Number of boxes of 6 shortbreads 
= 20 ÷ 5
= 4

Number of boxes of 11 shortbreads
= 13 - 4
= 9

Answer(s): (a) 123; (b) 9