A boat takes 76 minutes to go 32.2 km upstream. The ratio of the speed of the boat in still water to that of the stream is 9 : 8. How much approximate total time (in hours) will the boat take to go 44.9 km upstream and 57.8 km downstream?​

Correct option is A

Given:

Time to go 32.2 km upstream = 76 minutes

The ratio of the speed of the boat in still water to that of the stream is 9 : 8

We need to find the total time to go 44.9 km upstream and 57.8 km downstream

Formula Used: ​

Speed = $$\frac{Distance }{Time}$$ 

Solution: ​

Let speed of boat is B and speed of stream be S 

So, Speed of boat = 9x 

speed of stream = 8x 

Now,

9x - 8x = $$\frac{32.2\times 60 }{76} = \frac{483}{19}$$ km/h

x = $$\frac{483}{19}$$km/h

Time taken to cover 44.9 km upstream

= $$\frac{44.9 \times 19}{ 483} = 1.77$$ h

Time taken to cover 75.8 km downstrream;

= $$\frac{57.8\times 19}{17 \times483}=0.13$$ h

Now, total time = 1.77 + 0.13 = 1.9 hours