We know that,
Speed = Distance/Time
For 1st vehicle,
V1 = 1 km/1 min
V1 = 1 km/1/60 hr
V1 = 60 km/hr
For 2nd vehicle,
V2 = 1 km/2 min
V2 = 1 km/2/60 hr
V2 = 30 km/hr
For 3rd vehicle,
V3 = 1 km/3 min
V3 = 1 km/3/60 hr
V3 = 20 km/hr
1. Time-men speed (Vt)
Vt = ∑Vi/n
Vt = (60 + 30 + 20)/3
Vt = 110/3
Vt = 36.7 km/hr
2. Space-men speed (Vs)
∑fi/vi = 1/60 + 1/30 + 1/20 = 0.10
Vs = n/(∑fi/vi)
Vs = 3/0.10
Vs = 30 km/hr
