Correct Answer - Option 4 : 36 km/h
GIVEN:
Initial distance = 80 m
Distance after 30 sec = 120m
Car's speed = 60 km/h
FORMULA USED:
Speed = Distance/Time
km/h × 5/18 = m/s
CALCULATION:
Distance traveled by car in 30 sec = 60 × 5/18 × 30 = 500 m
Distance traveled by truck in 30 sec = 500 - (120 + 80) = 300 m
Speed of truck = 300/30 =10 m/s
⇒ 10 × 18/5 = 36 km/h
∴ Speed of truck is 36 km/h