There are 12 coins laid on a table and 4 are selected randomly. 8 Coins are heads up and 4 coins are Tails up.
a) What is the probability tht you will pick all 4 tails?
b) What is the probalbity that you will pick at most 2 tails?
a) P(4 tails) = 1 / 12C4
= 0.002
b) P(at most 2 tails) = P(2 heads) + P(3 heads) + P(4 heads)
= 4C2 * 8C2 / 12C4 + 4C1 * 8C3 / 12C4 + 8C4 / 12C4
= 0.594
Do these look alright?
a) What is the probability tht you will pick all 4 tails?
b) What is the probalbity that you will pick at most 2 tails?
a) P(4 tails) = 1 / 12C4
= 0.002
b) P(at most 2 tails) = P(2 heads) + P(3 heads) + P(4 heads)
= 4C2 * 8C2 / 12C4 + 4C1 * 8C3 / 12C4 + 8C4 / 12C4
= 0.594
Do these look alright?
