Let’s count – Uniform probability

Do your best in trying to solve the following problems. It is normal that this step will take some time, we recommend to perseverate and wait before looking at the complete solution of the exercises in the video or in the pdf below.

Exercise 1.

What is the probability that the two top cards in a deck of 52 cards do not form a pair, that is, are not two cards with the same value (from different suits)?

Exercise 2.

We extract, one after the other, two balls ramdomly chosen from a urn that contains 8 Red balls, 4 Black balls. 1. Find a sample space (Omega) for the uniform probability, that allows to describe events related to a first/second extraction, compute (vertOmegavert).
What is the probability that:
2a. The first ball is Red?
2b. The second is Red?
2c. Both are Red?