Answer:
5/16.
Explanation:
The probability of getting a correct answer on one question is 1/2 and the probability of getting it wrong is 1 - 1/2 = 1/2.
The probability of the first 2 being correct and the next 3 wrong = (1/2)^5 = 1/32.
There are 10 possible combinations of this ( first wrong the 2nd and third right and last 2 wrong, etc).
So the required probability is 10 * 1 /32
= 10/32
= 5/16.