Do the three would's have the same meaning in the following?
a. A: Who's ringing the doorbell? B: It'd (= would) be John.
b. I think my swimming pool would hold 20,000 gallons of water.
c. If I were a billionaire, I would buy a jet.
It seems that the "would" in (a) is a deductive usage, but I am not sure about (b) and (c).