Sorry in advance for the broad title guys, I couldn't find an appropriate term for these two probability questions.

1. Nicole and Ashley each chose a random number between 0 and 1, inclusive. What is the probability that the positive difference of the two numbers does not exceed 0.5?

2. Bob chooses a point at random on which to stand from the region $\displaystyle x^2+y^2<=100$. Frank, Bill, Sam, Rick, and an infinite amount of other people stand on all of the points from the region $\displaystyle x^2+y^2=100$. What is the probability that the largest distance between Bob and any of the other people is 12?

Not sure where to start on either of these... Any suggestions are appreciated!

P.S. The first equation from question 2 contains a less than or equal to symbol.