Nick had some apricot tarts and chocolate chip tarts. He gave away 100 tarts to his brother. 10% of them were apricot tarts and the rest were chocolate chip tarts.

1. How many chocolate chip tarts did he give his brother?
2. Nick gave some apricot tarts to his sister. ³₅ of all the tarts he gave away to his brother and his sister were apricot tarts. How many apricot tarts did he give his sister?

(a)
Percentage of chocolate chip tarts
= 100% - 10%
= 90%

Number of chocolate chip tarts that Nick gave to his brother
= 90% x 100
= ⁹⁰₁₀₀ x 100
= 90 

(b)
Fraction of all the tarts he gave away to his brother and his sister that were chocolate chip tarts
= 1 - ³₅
= ²₅

2 u = 90

1 u = 90 ÷ 2 = 45

Number of apricot tarts that Nick gave to his brother and his sister
= 3 u
= 3 x 45
= 135

Number of apricot tarts that Nick gave to his brother
= 100 - 90
= 10

Number of apricot tarts that Nick gave to his sister
= 135 - 10
= 125

Answer(s): (a) 90; (b) 125