STAR Test question: Why did I come up with the wrong answer

Today I took the STAR Test for math, and there was a problem I didn't get. Frank and Joe are in a foreign language class with 20 students. There is a special foreign language dinner, and the teacher is randomly selecting two students. What is the probability that she will pick both Frank and Joe? The options were 1/200, 1/190, and 2 others that I don't remember. I thought that the answer would be 1/20 times 1/19, which is 1/380, but that wasn't an option. Why not?

You were close! The probability of picking Frank, then Joe would be 1/380, as you computed. Then again, the probability of picking Joe, then Frank would be 1/380.

The answer would be 1/380 + 1/380 = 2/380 = 1/190

AMAZING!Is it you want?
http://cool10.info/132345/foreign-language-classes

You were close... 1/20 PLUS 1/19 = 2/380 or 1/190