When will they lose contact?

Question

A truck and car leave a service station at the same time and same direction. The truck travels at 60 mph and the car at 54 mph. They can maintain radio contact within a range of 12 miles. When will they lose contact?

 

They will lose contact after __ hrs

(Type integer or a decimal)

Answer 1

The question amounts to, how long will it be before their separation passes 12 miles?

 

The truck is traveling 6 mph faster than the car, so the separation between them is increasing by 6 miles every hour.  So they will be 12 miles apart after 12/6 = 2 hours.