Question

two buses leave at the same time from fresno but from oppisite directions. ones going 45 mi per hour and the other is going 55 miles per hour. how long will it take for them to be 400 miles away from each other

Answer 1

it's better this question to be on Physics section.

Answer 2

\[ R(r_{1}+r_{2})= r_{1} r_{2} for R\]