The rational number equivalent to the rational number $$\dfrac{7}{19}$$ is:
Correct option is D. $$\dfrac{21}{57}$$
$$\dfrac { 7 }{ 19 }$$ can be written as $$\dfrac { 7\times n }{ 19\times n } $$ where $$n$$ is integer.
The only equation which satisfies this equation is option D as
$$\dfrac{21}{57}=\dfrac{7\times 3}{19\times 3}$$
where $$n=3$$
So correct answer should be option D