PSLE
Tiffany baked some muffins. She gave ¹₂ of the muffins to her friends and 138 to her students. She was left with ¹₅ of the muffins. She packed these into 10 boxes. Some boxes contained 8 muffins while the rest contained 10 muffins.

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

(a)
Fraction of the muffins given to her students
= 1 - ¹₂ - ¹₅

= 1 - ⁵₁₀ - ²₁₀
= ³₁₀

Number of muffins that Tiffany gave to her students = 3 u

3 u = 138

1 u = 138 ÷ 3 = 46

Number of muffins that were packed in 10 boxes
= 2 u
= 2 x 46
= 92

Number of muffins that were packed in 10 boxes = 92

Boxes of 10	Muffins	Boxes of 8	Muffins	Total muffins
10	100	0	0	100
9	90	1	8	98

If all the muffins are packed in boxes of 10, the number of muffins needed
= 10 x 10
= 100

Small difference
= 100 - 98
= 2

Big difference
= 100 - 92
= 8

Number of boxes of 8 muffins 
= 8 ÷ 2
= 4

Number of boxes of 10 muffins
= 10 - 4
= 6

Answer(s): (a) 92; (b) 6