Out of 16 Squares on a Board, Two Squares Are Chosen at Random. The Probability That They Have No Side in Common Is
A 4×4 board has 16 squares. Two are chosen at random. Find the probability they share no side, by counting adjacent pairs directly.
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Two Persons A and B Throw a Pair of Dice Alternately. A Wins if He Throws a Sum of 5 Before B Throws a Sum of 8. If A Throws First, the Probability That A Wins Is
A and B alternately throw a pair of dice; A wins by throwing sum 5 before B throws sum 8. Full solution using independent events and an infinite GP.
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A Committee of 4 Students Is Selected at Random From a Group Consisting of 8 Boys and 4 Girls. Given That There Is at Least One Girl in the Committee, Find the Probability That There Are Exactly 2 Girls
A committee of 4 is chosen from 8 boys and 4 girls. Given at least one girl is selected, find the probability of exactly 2 girls, using the conditional probability formula.