$\frac{4}{8}\times\frac{0.05}{2}\div\frac{0.2}{20}$  

(a)  

 $\frac{12}{144}\div\frac{?}{.03}=\frac{1}{40}$  

(a)  

 $\frac{12}{?}\div\frac{2.5}{100}=20$  

(a)  

 $\frac{7}{35}\div\frac{?}{10}=1$  

(a)  

 $\frac{9}{729}\left(3\frac{1}{5}+2\frac{1}{5}\right)$  

(a)  

 $\frac{0.005}{2}\times\frac{20}{0.2}\div\frac{1}{8^2}$  

(a)  

 $\frac{0.1}{2}\div0.2\times2^2$  

(a)  

 $2^2+3^2+\left(3^3\div3^5\right)$  

(a)  

 $\frac{2^2}{3^5}\div\frac{2^4}{3^3}$  

(a)