Each of the total fice questions in amultiple choice examination has four choices, only one of which is correct.A student is attempting to guess the amswer . The renadom varible X is the number of question answerred correctly. What is the probability that the student will giveat least one correct answer ?

Explanation

Let p = probability that the given answer is correct. Q= probability that the given answer is wrong. `p=(1)/(4),q=1-(1)/(4)=(3)/(4)` P
Probability that the student will given wrong answers of all questions.
`=(3)/(4)xx(3)/(4)xx(3)/(4)xx(3)/(4)xx(3)/(4)`
`=(243)/(1024)`
Probability that the student will given at least one correct answer
`=1-(243)/(1024)`