Sean had some strawberry doughnuts and cherry doughnuts. He gave away 100 doughnuts to his sister. 40% of them were strawberry doughnuts and the rest were cherry doughnuts.

1. How many cherry doughnuts did he give his sister?
2. Sean gave some strawberry doughnuts to his brother. ⁴₇ of all the doughnuts he gave away to his sister and his brother were strawberry doughnuts. How many strawberry doughnuts did he give his brother?

(a)
Percentage of cherry doughnuts
= 100% - 40%
= 60%

Number of cherry doughnuts that Sean gave to his sister
= 60% x 100
= ⁶⁰₁₀₀ x 100
= 60 

(b)
Fraction of all the doughnuts he gave away to his sister and his brother that were cherry doughnuts
= 1 - ⁴₇
= ³₇

3 u = 60

1 u = 60 ÷ 3 = 20

Number of strawberry doughnuts that Sean gave to his sister and his brother
= 4 u
= 4 x 20
= 80

Number of strawberry doughnuts that Sean gave to his sister
= 100 - 60
= 40

Number of strawberry doughnuts that Sean gave to his brother
= 80 - 40
= 40

Answer(s): (a) 60; (b) 40