PSLE
Wendy baked some cupcakes. She gave ¹₂ of the cupcakes to her relatives and 141 to her friends. She was left with ¹₅ of the cupcakes. She packed these into 11 boxes. Some boxes contained 6 cupcakes while the rest contained 10 cupcakes.

1. How many cupcakes were packed into the 11 boxes?
2. How many boxes contained 10 cupcakes?

(a)
Fraction of the cupcakes given to her friends
= 1 - ¹₂ - ¹₅

= 1 - ⁵₁₀ - ²₁₀
= ³₁₀

Number of cupcakes that Wendy gave to her friends = 3 u

3 u = 141

1 u = 141 ÷ 3 = 47

Number of cupcakes that were packed in 11 boxes
= 2 u
= 2 x 47
= 94

Number of cupcakes that were packed in 11 boxes = 94

Boxes of 10	Cupcakes	Boxes of 6	Cupcakes	Total cupcakes
11	110	0	0	110
10	100	1	6	106

If all the cupcakes are packed in boxes of 10, the number of cupcakes needed
= 11 x 10
= 110

Small difference
= 110 - 106
= 4

Big difference
= 110 - 94
= 16

Number of boxes of 6 cupcakes 
= 16 ÷ 4
= 4

Number of boxes of 10 cupcakes
= 11 - 4
= 7

Answer(s): (a) 94; (b) 7