A motor boat covers 16 km in 2 hours downstream and 14 km in 2 hours upstream. The speed of the motor boat is:

7.5 km/hr

The correct answer is Option (4) - 7.5 km/hr

$\text{Downstream speed} = \frac{16}{2} = 8 \text{ km/hr}$

$\text{Upstream speed} = \frac{14}{2} = 7 \text{ km/hr}$

$u = \frac{8 + 7}{2} = 7.5 \text{ km/hr}$

The speed of the motor boat is $7.5$ km/hr.