A boat can row upstream at 12 km/h and downstream at 20 km/h. Find the speed of boat in still water and the speed of the stream.

16 km/h, 4 km/h

The correct answer is Option (4) → 16 km/h, 4 km/h

$\text{Upstream speed} = u - v = 12$

$\text{Downstream speed} = u + v = 20$

$u = \frac{12 + 20}{2} = 16$

$v = \frac{20 - 12}{2} = 4$

Speed of boat in still water is $16$ km/h and speed of stream is $4$ km/h.