a) $\frac{1}{5}$  liczby $2$  wynosi $\frac{2}{5}$  

(bo $\frac{1}{5}\cdot 2=\frac{2}{5}$ )

b) $\frac{3}{4}$  liczby $1$  wynosi $\frac{3}{4}$  

(bo $\frac{3}{4}\cdot 1=\frac{3}{4}$ )

c) $\frac{2}{21}$  liczby $9$  wynosi $\frac{18}{21}$  

(bo $\frac{2}{21}\cdot 9=\frac{18}{21}$ )

d) $\frac{1}{5}$  liczby $10$  wynosi $2$  

(bo $\frac{1}{5}\cdot 10=\frac{10}{5}=2$ )

e) $\frac{1}{2}$  liczby $8$  wynosi $4$  

(bo $\frac{1}{2}\cdot 8=\frac{8}{2}=4$ )

f) $\frac{3}{4}$  liczby $12$   wynosi $9$  

(bo $\frac{3}{4}\cdot 12=\frac{36}{4}=9$ )