A person has to cover a distance of 6 km in 45 minutes .If he covers half of the distance in two-third of the total time to cover the remaining distance in the remaining time, his speed must be
Remaining distance = $$\frac{6}{2}$$ = 3 km
Remaining time = $$45 * \frac{1}{3}$$ = 15 minutes
Required speed = $$\frac{3}{15} * 60$$ = 12 km/h