Question

Compute the probability of each event. In each case, you must combine the general disjunction rule with either the restricted disjunction rule or the general conjunction rule. Reduce your answer to the lowest whole numbers. Indicate your answers by typing numeric responses into the spaces provided.

When rolling a pair of eight-sided dice, what is the probability of getting either a two (Event T) or a four (Event F) on the first die or either a two or a four on the second die?

Probability expressed as a fraction: ?/?

Assume there is a pair of jars. The first jar contains two blue balls, three green balls, and no red balls. The second jar contains one blue ball, three green balls, and 1 red ball. What is the probability of drawing first a blue ball (event B) and then a green ball (event G) from either of the two jars, having drawn twice from each with no replacements?

Probability expressed as a fraction: ?/?

Logic 2500

Answer 1

When rolling a pair of eight-sided dice, what is the probability of getting either a two (Event T) or a four (Event F) on the first die or either a two or a four on the second die?

getting 2 or 4 on a die = 2/8 = 0.25

P(A or B) = P(A) + P(B) - P(A and B)

A - 2 or 4 on first die

B - 2 or 4 on second die

we need P(A or B)

P(A) = P(B) = 0.25

P(A and B) = P(A)P(B) = 0.25*0.25 = 0.0625

hence P(A or B) = 0.25 + 0.25 - 0.0625

= 0.4375