Once you attempt the question then PrepInsta explanation will be displayed.

Let the rate upstream of the ship= x kmph

& the rate downstream of the ship = y kmph

Distance travelled upstream in 8⅘ hrs = Distance travelled downstream in 4 hrs.

Since distance is same in both the cases and distance = speed × Time

∴ x × 8⅘ = y × 4

⇒ x × 44/5 = y × 4 ⇒ x × 11/5 = y ....... (1)

Now, we know that-

Speed in still water = \frac{1}{2} (x+y) km/h

Rate of stream = \frac{1}{2} (y-x) km/h

Hence, Speed Titanic = \frac{x+y}{2}

Speed of water = \frac{y-x}{2}

∴ Required ratio = \left ( \frac{x+y}{2} \right ) : \left ( \frac{y-x}{2} \right )

= (y+x) : (y-x)

= \left ( \frac{11x}{5}+x \right ) : \left ( \frac{11x}{5}-x \right )

= (11x+5x) : (11x-5x) = 8:3