A pair of dice is rolled. What is the probability that the sum of the two numbers is exactly 8?

Medicine Out of a group of 9 patients treated with a new drug, 4 suffered a relapse. Find the probability that 3 patients of this group, chosen at random, will remain disease-free.

You draw one card at random from a standard deck of 52 playing cards. What is the probability that the card is either an ace or a spade?

Determine if the statement is true or false. If the statement is false, then correct it and make it true. If the probability that you will graduate is 0.63, then the probability that you will not graduate is -0.63.