correct answer is: c) 16 : 24 : 30 : 35

Explanation

Here, A : B = 2 : 3, B : C = 4 : 5 and C : D = 6 : 7 .
To find A : B : C : D, First we will equalize the value of 'C' and then equalize the value of 'B' then the values of 'A' and 'D' will also be extracted.

\large\frac{A}{B}\normalsize=\large\frac{2\times8}{3\times8}\normalsize=\large\frac{16}{24}
\large\frac{B}{C}\normalsize=\large\frac{4\times6}{5\times6}\normalsize=\large\frac{24}{30}
\large\frac{C}{D}\normalsize=\large\frac{6\times5}{7\times5}\normalsize=\large\frac{30}{35}
\therefore A : B : C : D=16 : 24 : 30 : 35
Ans: 16 : 24 : 30 : 35 .