b. I'm trying to recall without looking it up. I think it's along the lines of e−1/x+e−1/(1−x)e−1/x, which goes to 1 as x approaches 1, 0 as x approaches 0, and 0.5 when x=0.5.
It doesn't matter how much time has passed since the last block was found. You always expect it to take 10 more minutes to find a block.
Same as @Murch for a.
b. I'm trying to recall without looking it up. I think it's along the lines of e−1/x+e−1/(1−x)e−1/x, which goes to 1 as x approaches 1, 0 as x approaches 0, and 0.5 when x=0.5.
It doesn't matter how much time has passed since the last block was found. You always expect it to take 10 more minutes to find a block.