Hi, we're having trouble figuring out the optimization of the minimum distance between two boats using calculus. The question was given to us like this:

At noon, ship A is 100 kilometers due east of ship B. Ship A is sailing west at 12 kilometers per hour and ship B is sailing south at 10 kilometers per hour. At what time will the ships be nearest to each other, and what will this distance be?

Your help would be most appreciated!!!!!!!!!!