Distance between camp A and Camp B = 600 m
Time takes to cover this distnace = 1 minute = 60 seconds
The speed of the cycle = 600/60= 10m/sec
Now time reduced to 40 seconds to cover the same distance , so the speed of the cycle = 600/40 = 15m/sec
Increase in the speed of the cycle = 15-10 = 5m/sec