1. (13%) State the definition of o -algebra. Explain the concept of σ -algebra.

3. (10%) Suppose we are playing draw poker. We are dealt (from a well shuffled deck) 5 cards which contain 4 spades and another card of a different suite. We decide to discard the card of a different suite and draw one card from the remaining cards to complete a flush in spades (all 5 cards spades). Determine the probability of completing the flush.