A cyclist usually takes 6 hours

Solution

ATQ, Usual speed of the cyclist = (240/6) = 40 km/h New speed of the cyclist = 0.25 × 40 = 10 km/h New time taken = (240/10) = 24 hours Alternate Solution: Let the usual speed of the cyclist be 10x km/hr. Therefore, decreased speed = 2.5x km/hr Since the distance covered is the same and time taken is inversely proportional to the speed: Ratio of time taken with usual speed to time taken with reduced speed = 6:24 = 1:4 Required time taken = 6 × (4/1) = 24 hours