If A : B = 2 : 5, B : C = 4 : 3 and C : D = 2 : 1, then what is value of A : C : D?

Given : $$\frac{A}{B}=\frac{2}{5}$$ -----------(i)

$$\frac{B}{C}=\frac{4}{3}$$ -----------(ii)

and $$\frac{C}{D}=\frac{2}{1}$$ -----------(iii)

Multiplying equation (ii) by 10 and (iii) by 15 to make 'C' equal in both

=> $$\frac{B}{C}=\frac{40}{30}$$ and $$\frac{C}{D}=\frac{30}{15}$$

Now, multiplying equation (i) by 8 to make 'B' equal in both

=> $$\frac{A}{B}=\frac{16}{40}$$

Thus, we get = $$A:B:C:D=16:40:30:15$$

$$\therefore$$ A : C : D = 16 : 30 : 15

=> Ans - (D)