PSLE
Gabby baked some puffs. She gave ¹₁₀ of the puffs to her students and 96 to her colleagues. She was left with ¹₂ of the puffs. She packed these into 18 boxes. Some boxes contained 5 puffs while the rest contained 8 puffs.

1. How many puffs were packed into the 18 boxes?
2. How many boxes contained 8 puffs?

(a)
Fraction of the puffs given to her colleagues
= 1 - ¹₁₀ - ¹₂

= 1 - ¹₁₀ - ⁵₁₀
= ⁴₁₀

Number of puffs that Gabby gave to her colleagues = 4 u

4 u = 96

1 u = 96 ÷ 4 = 24

Number of puffs that were packed in 18 boxes
= 5 u
= 5 x 24
= 120

Number of puffs that were packed in 18 boxes = 120

Boxes of 8	Puffs	Boxes of 5	Puffs	Total puffs
18	144	0	0	144
17	136	1	5	141

If all the puffs are packed in boxes of 8, the number of puffs needed
= 18 x 8
= 144

Small difference
= 144 - 141
= 3

Big difference
= 144 - 120
= 24

Number of boxes of 5 puffs 
= 24 ÷ 3
= 8

Number of boxes of 8 puffs
= 18 - 8
= 10

Answer(s): (a) 120; (b) 10