Question

Three fair coins are flipped. What is the probability that at least 2 of them come up heads?

Answer 1

The probability that atleast 2 of them come up heads is 0.5

∴ P(A)=0.5

Explanation:

Given that three fair coins are flipped.

To find the probability that at least 2 of them come up heads:

Sample space for the given event is

`S={\{HHH, HHT, HTH, HTT, THH, THT, TTH, TTT}\}`

∴ n(S)=8

Let A be the events of getting atleast 2 Heads and is given by

A = {HHH, HHT, HTH, THH}

∴ n(A)=4

Probability of Getting atleast 2 Heads in 3 Coin Tosses is

`P(A)=(n(A))/(n(S))`

`P(A)=(4)/(8)`

`=0.5`

∴ P(A)=0.5

∴ the probability that atleast 2 of them come up heads is 0.5