A 150 m train takes 10 seconds to cross another train 100 m long coming from the opposite direction. If the speed of first train is 30 km/hr, what is the speed of second train?

• ক 54 km/hr
• খ 72 km/hr
• গ 48 km/hr
• ঘ 60 km/hr ✅ সঠিক উত্তর