PSLE
Jane baked some scones. She gave ¹₅ of the scones to her students and 81 to her colleagues. She was left with ¹₂ of the scones. She packed these into 15 boxes. Some boxes contained 6 scones while the rest contained 11 scones.

1. How many scones were packed into the 15 boxes?
2. How many boxes contained 11 scones?

(a)
Fraction of the scones given to her colleagues
= 1 - ¹₅ - ¹₂

= 1 - ²₁₀ - ⁵₁₀
= ³₁₀

Number of scones that Jane gave to her colleagues = 3 u

3 u = 81

1 u = 81 ÷ 3 = 27

Number of scones that were packed in 15 boxes
= 5 u
= 5 x 27
= 135

Number of scones that were packed in 15 boxes = 135

Boxes of 11	Scones	Boxes of 6	Scones	Total scones
15	165	0	0	165
14	154	1	6	160

If all the scones are packed in boxes of 11, the number of scones needed
= 15 x 11
= 165

Small difference
= 165 - 160
= 5

Big difference
= 165 - 135
= 30

Number of boxes of 6 scones 
= 30 ÷ 5
= 6

Number of boxes of 11 scones
= 15 - 6
= 9

Answer(s): (a) 135; (b) 9