The ratio of the incomes of Ram and Shyam is 7 : 17 and that of Shyam and Sohan is 7 : 17. If the income of Ram is Rs. 490, what is the income of Sohan ?

Answer: Option D

$$\begin{array}{rl}& \text{Ram}:\text{Shyam}=7:17\\ & \text{Shyam}:\text{Sohan}=7:17\\ & =\left(7\times \frac{17}{7}\right):\left(17\times \frac{17}{7}\right)\\ & =17:\frac{289}{7}\\ & \text{Ram}:\text{Shyam}:\text{Sohan}\\ & =7:17:\frac{289}{7}\\ & =49:119:289\end{array}$$
Let Sohan's income be Rs. x
Then,
= 49 : 289 :: 490 : x or x = 2890