Three runners on a 2.5 km circular track start at the same point with speeds 8, 10 and 12 km/h. From 9 am to 3 pm, how many times do they meet at the start?

उत्तर दाखवा आणि स्पष्टीकरण

उत्तर: (C) 5 times

स्पष्टीकरण

Lap times 18.75, 15 and 12.5 min have LCM 75 min. In 360 min they meet at 75, 150, 225, 300; the key's 5 also counts the 9 am start.