A car that moves at an average speed of 60 kmph, reaches its destination on time. When its average speed becomes 50 kmph, then it reaches its destination 45 minutes late. Find the length of journey.	Choose the most appropriate option
A) 189 km
B) 225 km
C) 255 km
D) 199 km
E) None
Sol.   Difference between timings = 45 min = 3/4 hr.   Let the length of journey be x km.   Then, x/50 - x/60 = 1/4   â‡” 6x - 5x = 225   â‡” x = 225 km.   Answer 225 km
<result>B</result>
A car that moves at an average speed of 60 kmph, reaches its destination on time. When its average speed becomes 50 kmph, then it reaches its destination 45 minutes late. Find the length of journey.