Option 2 : 2.88 km

Given:

The speed of the boat = 6 km/h

The speed of the stream = 1.2 km/h

Time taken by the boat to go to a place and comeback = 1 hours

Formula Used:

Upstream speed = (Speed of the boat) - (Speed of the stream)

Downstream speed = (Speed of the boat) + (Speed of the stream)

Distance = Speed × Time

Calculation:

Upstream speed = (6 - 1.2) km/h

⇒ 4.8 km/h

Downstream speed = (6 + 1.2) km/h

⇒ 7.2 km/h

Let the distance of the place be x km.

According to the question,

(x/7.2) + (x/4.8) = 1

⇒ 4.8x + 7.2x = 7.2 × 4.8

⇒ 12x = 7.2 × 4.8

⇒ x = 2.88

∴ The distance of the place will be 2.88 km.

__Additional Information__

1) Upstream: The boat or a swimmer moving against the stream is known as moving upstream (against the flow of water).

2) Downstream: The boat or a swimmer moving along the stream is known as moving downstream (along the flow of water).

3) If the speed of the boat or swimmer is X km/hr and the speed of the stream is Y km/hr,

a) The speed of the boat or swimmer in the direction of the stream is known as speed downstream. It is given by;

Speed downstream = (X + Y) km/hr

b) And, the speed of the boat or swimmer against the stream is known as speed upstream. It is given by;

Speed upstream = (X - Y) km/hr