A boat whose speed is the same as the speed of a car, i.e., x x x km/hr, can travel d d d km upstream and return to the initial point in 8 1 3 8 \frac...

A boat whose speed is the same as the speed of a car, i.e., $x$ km/hr, can travel $d$ km upstream and return to the initial point in $8 \frac{1}{3}$ hours. The time taken by the car to cover the total distance traveled by the boat is $\frac{1}{3}$ hour less than that taken by the boat. If the time taken by the boat to cover $18$ km downstream is $30$ minutes more than the time taken to cover $6$ km upstream, and the speed of the stream is $y$ km/hr, then which of the following options is equal to the time taken by the boat to cover $(2d + 90)$ km in still water?

(i) $\frac{d}{x - y} + 3y$

(ii) $\frac{d}{x - y} - 3y$

(iii) $\frac{180}{x + y} + 4$

Choose the correct option: