Question

What is the probability of getting at least 2 heads and four coins are tossed

Answer 1

Explanation:

Probability density for 4 coins is

Probability density for 4 coins is4 heads 0 tails = 1/16

Probability density for 4 coins is4 heads 0 tails = 1/163 heads 1 tails = 4/16

Probability density for 4 coins is4 heads 0 tails = 1/163 heads 1 tails = 4/162 heads 2 tails = 6/16

Probability density for 4 coins is4 heads 0 tails = 1/163 heads 1 tails = 4/162 heads 2 tails = 6/161 heads 3 tails = 4/16

Probability density for 4 coins is4 heads 0 tails = 1/163 heads 1 tails = 4/162 heads 2 tails = 6/161 heads 3 tails = 4/160 heads 4 tails = 1/16

hope it's help you....

Answer 2

Explanation:

This answer can be generalized to tossing N fair coins simultaneously, and getting R heads (and N - R tails). Now line the coins up in any you wish.

What is the probability of getting R heads?

First, the heads can be in any of the R positions out of the N possible positions.

The number of ways of doing this is (NR) .

To get the probability, we divide this by the total number of ways you can flip N coins, which is 2N , since each coin can be a heads or a tail.

So the probability is (NR)2N .

Now that we have a general answer, we can plug in your numbers to get your particular answer.

(NR)2N=(42)24=6/16=3/8 .