Assume that they meet x hours after 10 a.m. Then, train 1, starting from A, travels x hours till the trains meet. Distance travelled by train 1 in x hours = 75x km Train 2, starting from B, travels (x − 1) hours till the trains meet. Distance travelled by train 2 in (x − 1) hours = 60(x − 1) km Total distance travelled = Distance travelled by train 1 + Distance travelled by train 2 ⇒ 300 = 75x + 60(x − 1) ⇒ 5x + 4(x − 1) = 20 ⇒ 5x + 4x − 4 = 20 ⇒ 9x = 20 + 4 ⇒ 9x = 24 ⇒ x = 24/9 = 2.67 hours = 2 hours 40 min Hence, the trains meet at 12:40 p.m.