Thread: 2 Trucks Traveling Towards Each Other

A 60-ft truck doing 40 mph is approaching a 40-ft truck doing 50 mph on a two lane road. How long (in seconds) does it take them to pass each other?

I'm at a loss. I tried every possible rate * time = distance formula that I know. I converted mph to ft/s. It just seems like there's not enough information to solve the problem. Without knowing the distance, the time could be anything.

The answer is 0.76.

It seems like t1 = t2 and d1 = d2. However, doing that causes 40 mph = 50 mph, and that's not right.



Thank you!

Distance to be travelled: 100 feet (from the back of each truck when they "meet")

This distance is travelled at 90 mph (sum of both speeds).

90 mph = 475200 feet per hour = 7920 feet per minute = 132 feet per second

100 / 132 = ~.76 seconds