How many kilometres from the starting point will the two vehicles draw level?

Question

Two vehicles set off from the same point to travel the same journey.

The first vehicle sets off four minutes before the second vehicle.

If the first vehicle travels at 55 km/h and the second vehicle travels at 75 km/h, how many kilometres from the starting point will the two vehicles draw level?

Answer 1

11 minutes.
.
The 1st vehicle travels at 55 km/h = 0.91667 km/min
Thus in the 4 minutes it has traveled 3.667 km.
The 2nd vehicle travels at 75 km/h, which is 20 km/h = 0.333 km/min faster.
The 3.667 km will be covered in 3.667 / 0.333 = 11 minutes.

Answer 2

Vehicle 1 will travel the distance in 4 + t
Vehicle 2 will travel the distance in t
Being t , time spent in minutes
We can write the following equation:
55 Km/hr x (4 + t)/60 = 75 Km/hr x t , t = 11 minutes
Then,
55 x (4 + 11)/60 = 13.75 Kms