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<h2>Check the explanation.</h2>Step-by-step explanation:
As all the questions of the exam carry 2 points, at least questions need to be correct to get 56 marks.
In order to get a maximum of 56 marks, at most 28 answers needs to be correct.
Every question has two option. Hence, the probability of getting a particular question right is .
The probability that exactly n questions will be right is .
The probability that at most 28 questions will be right is ∑,
.
Similarly, the probability that at least 30 questions will be right is ∑,
.