The probability of a man hitting man hitting target is 0.25. If he shoots 7 times, then what is the probability of his hittiing atleast twice ?

Answer

`(4547)/(8192)`

Explanation

`p=(1)/(4),q=(1-(1)/(4))=(3)/(4) " and " n=7`
`P(X=r) =.^(n)C_(r ).p^(r ).q^((n-r)) =^(7)C_(r ).((1)/(4))^(r ).((3)/(4))^((n-r))`
`P(X ge 2)=1 -P(Xlt 2)`
`=1-P[(X=0) " or " (X =1)]`
`=1- [P(x=0 ) +P(X =1)]`