# Question #4b96c

Aug 25, 2016

Suppose the cars start at the same time and collide with each other after time $t$ hours

Distance traveled by car A in this time$= \text{ Displacement}$
$= \text{Speed"xx"Time}$
$= 20 \times t \text{ miles}$
Similarly distance traveled by car B in the same time$= 35 \times t \text{ miles}$
At the time of collision total distance traveled by both cars must be $= 60 \text{ miles}$
$\therefore$ we have
$20 t + 35 t = 60$
$\implies 55 t = 60$
Solving for $t$ we obtain
$t = \frac{60}{55} \approx 1 \text{ hr "5 " m "27" s }$