A train X leaves Howrah at 6 a.m. and reaches Asansol at 10 a.m. Another train Y leaves Asansol at 8 a.m. and reaches Howrah at 11.30 a.m. The two trains cross one another at

Time taken by train X to reach destination = 4 hours and time taken by train Y = 3.5 hours

Let distance between Howrah and Asansol = L.C.M. (4,3.5) = 28 km

=> Speed of train X = $$\frac{28}{4}=7$$ km/hr

and speed of train Y = $$\frac{28}{3.5}=8$$ km/hr

If the two trains meet after $$t$$ hours from 6 a.m., then

=> $$7t+8(t-2)=28$$

=> $$15t=28+16=44$$

=> $$t=\frac{44}{15}$$ hours

=> $$t=\frac{44}{15}\times60=176$$ minutes = 2 hours 56 minutes

$$\therefore$$ The two trains cross one another at = 8.56 a.m.

=> Ans - (B)