The distance between two cities A and B is 330 km. A train starts from A at 8 a.m. and travel towards B at 60 km/hr. Another train starts from B at 9 a.m. and travels towards A at 75 Km/hr. At what time will they meet?	Choose the correct answer:  A) 10.30 a . m  B) 11 a . m  C) 10 a . m  D) 12 noon  E) none of these

Rationale: "explanation : assume that they meet x hours after 8 a . m . then , train 1 , starting from a , travelling towards b , travels x hours till the trains meet ⇒ distance travelled by train 1 in x hours = speed × time = 60 x then , train 2 , starting from b , travelling towards a , travels ( x - 1 ) hours till the trains meet ⇒ distance travelled by train 2 in ( x - 1 ) hours = speed × time = 75 ( x - 1 ) total distance travelled = distance travelled by train 1 + distance travelled by train 2 = > 330 = 60 x + 75 ( x - 1 ) = > 12 x + 15 ( x - 1 ) = 66 = > 12 x + 15 x - 15 = 66 = > 27 x = 66 + 15 = 81 = > 3 x = 9 = > x = 3 hence the trains meet 3 hours after 8 a . m . , i . e . at 11 a . m . answer : option b"
Answer: B