Kindly note that the question says 4; maybe the final question was intended to be the probability that he gets exactly 2 of the 4 correct. However. If it is the other way round. This a e procedure used in the solution should also be followed.
Answer:
0.21
Step-by-step explanation:
Number of options = 4
One correct answer per option ; hence, the probability of success, p = 1/4 = 0.25
Using the binomial probability relation :
P(x =x) = nCx * p^x * (1 - p)^(n - x)
x = 2 ; n = 4
p = 0.25 ; 1 - p = 0.75
P(x = 2) = 4C2 * 0.25^2 * 0.75^2
P(x = 2) = 6 * 0.0625 * 0.5625
P(x = 2) = 0.2109375
P(x = 2) = 0.21 (2 decimal places)
Note : if the question was 3, then put, n = 3 instead of 4
