If A : B = 2 : 3, B : C = 4 : 5 and C : D = 5 : 9 then A : D is equal to:

Answer: Option B

$$\begin{array}{rl}& \frac{A}{D}=\frac{A}{B}\times \frac{B}{C}\times \frac{C}{D}\\ & =\frac{2}{3}\times \frac{4}{5}\times \frac{5}{9}\\ & =\frac{2\times 4\times 5}{3\times 5\times 9}\\ & =\frac{8}{27}\\ & =8:27\end{array}$$