Two bicycles depart from Miami Beach going in opposite directions. The first bicycle is traveling at 10 miles per hour. The second bicycle travels at 5 miles per hour. How long does it take until the bikes are 45 miles apart?

I know its 3 hours, but i dont know how to find it the proper way.

Question

Two bicycles depart from Miami Beach going in opposite directions. The first bicycle is traveling at 10 miles per hour.  The second bicycle travels at 5 miles per hour. How long does it take until the bikes are 45 miles apart?

I know its 3 hours, but i dont know how to find it the proper way.

anonymous · Answer

D=RT
45=(10+5)T
45=15T
T=445/15
T=3 HOURS ANS.