Trong các phân số sau, phân số nào là phân số tối giản?

A. $\dfrac{9}{{20}}$

B. $\dfrac{9}{{11}}$ 

C. $\dfrac{{11}}{{20}}$       

D. $\dfrac{{11}}{9}$

A. $\dfrac{7}{4}$

B. $2\dfrac{3}{4}$

C. $2\dfrac{4}{3}$

D. $1\dfrac{3}{4}$

A. $\dfrac{{456}}{{1000}}$

B. $\dfrac{{544}}{{1000}}$

C. $\dfrac{{544}}{1}$

D. $\dfrac{{456}}{{100}}$

A. $\dfrac{{15}}{9}$   

B. $\dfrac{5}{3}$

C. $\dfrac{7}{5}$

D. $\dfrac{{25}}{{15}}$

A. $\dfrac{2}{3}$

B. $\dfrac{{16}}{{24}}$

C. $\dfrac{{48}}{{72}}$

D. Cả A, B, C đều đúng

A. $\dfrac{{15}}{{24}};\,\,\dfrac{{21}}{{24}}$

B. $\dfrac{6}{9};\,\,\dfrac{6}{8}$

C. $\dfrac{8}{{12}};\,\,\dfrac{9}{{12}}$

D. $\dfrac{9}{{12}};\,\,\dfrac{8}{{12}}$