How many kilometers from the starting point will they draw level?

Question

Two cars set off from the same point and travel the same route.

The first car has a start of nine minutes before the second car sets off.

If the first car travels at 55 km/h and the second car travels at 60 km/h, how many kilometres from the starting point will they draw level?

Answer 1

99 kms.
let distance traveled by 2 cars be x kms.
therefore time taken by car 1 =x/55 hours .
also time taken by car 2 =x/60 hours .
difference in time = 9 min. =9/60 hours.
therefore time taken by car 1 -time taken by car 2 =9/60.
=> x/55-x/60=9/60.
x/11-x/12=9/12.
LCM=132.
12*x-11*x=(132*9)/12.
x=9*11.
x=99 kms.