Walking at 5/6 of its usual speed, a train is 10 minutes too late. Find its usual time to cover the journey. Choose the correct choice from the following choices.
A) 50 min
B) 20 min
C) 1 hour
D) 30 min
E) 45 min

Rationale: "new speed = 5 / 6 of the usual speed new time taken = 6 / 5 of the usual time taken so , ( 6 / 5 of the usual time ) - ( usual time ) = 10 min 1 / 5 of the usual time = 10 min usual time = 10 * 5 = 50 min correct option is a"
Answer: A