Five people are at sea in a boat which is leaking. There is already a certain amount of water in the boat, and more water is coming in at a constant rate.

Fortunately, there are five buckets in the boat! It is determined that:

• If three people start pouring water out of the boat, it will take 12 minutes for the boat to be empty.
• If four people start pouring water out of the boat, it will take 6 minutes for the boat to be empty.

Naturally, all five people can pour out water at the same constant rate.

a) How long would it take all five people to empty the boat?

b) How long would it take two people to empty the boat?

c) If the leak was fixed immediately, how long would it take three people to empty the boat?