4. Compound Probability
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Use the formula for the probability of overlapping events.
5/8
In order to find the desired probability, we will find the individual probabilities and the probability that we select a card that is both red and greater than 5. Let's start by calculating the probability of choosing a red card.
Out of 40 cards, there are 10 red cards. P( red card)= 10/40=1/4 Next, we will calculate the probability of choosing a card greater than 5.
Out of 40 cards, there are 20 cards greater than 5. P( card greater than5)= 20/40=1/2 Now we will calculate the probability of both choosing a red card and choosing a card greater than 5.
P(A or B)= P(A) + P(B)-P(A and B)
Substitute values
a/b=a * 2/b * 2
a/b=a * 4/b * 4
Add and subtract fractions