A train moves at average speed of 40kmph reaches its destination on time.what its average speed becomes 35kmph , then it reaches its destination 15 late. find the length of the journey?	Select the correct option
A) 70 km
B) 85 km
C) 38 km
D) 14 km
E) 1 km

Rationale: difference between timings = 15 mis = 1 / 4 hr let the length of the journey be x km . then x / 35 - x / 40 = 1 / 4 8 x - 7 x = 70 x = 70 km answer ( a )
Answer: A