Ian had some chocolate chip muffins and cheese muffins. He gave away 200 muffins to his cousin. 20% of them were chocolate chip muffins and the rest were cheese muffins.

1. How many cheese muffins did he give his cousin?
2. Ian gave some chocolate chip muffins to his brother. ⁵₇ of all the muffins he gave away to his cousin and his brother were chocolate chip muffins. How many chocolate chip muffins did he give his brother?

(a)
Percentage of cheese muffins
= 100% - 20%
= 80%

Number of cheese muffins that Ian gave to his cousin
= 80% x 200
= ⁸⁰₁₀₀ x 200
= 160 

(b)
Fraction of all the muffins he gave away to his cousin and his brother that were cheese muffins
= 1 - ⁵₇
= ²₇

2 u = 160

1 u = 160 ÷ 2 = 80

Number of chocolate chip muffins that Ian gave to his cousin and his brother
= 5 u
= 5 x 80
= 400

Number of chocolate chip muffins that Ian gave to his cousin
= 200 - 160
= 40

Number of chocolate chip muffins that Ian gave to his brother
= 400 - 40
= 360

Answer(s): (a) 160; (b) 360