Rashmi walks to her bus stop at 5 kmph and reaches there late by 10 minutes. On the next day,she increases her speed to 6 kmph and reaches the bus stop 10 minutes early.How far is the bus stop ?	Choices
A) 13	B) 12	C) 11	D) 10	E) 9

Rationale: let the distance to the bus stop is ` ` d ' ' km time taken by her ( at 5 kmph ) = d / 5 hour , and time taken by her ( at 6 kmph ) = d / 6 hour as per given condition , d / 5 - d / 6 = 20 / 60 d = 10 kms answer : d
Answer: D