Answer:
A.
Step-by-step explanation:
Firstly, we should know that this problem is a Bernoulli trial problem.
We shall be using the equation of the trial later in the question.
We know that there are 5 options per questions, this mean that there are a total of 10 × 5 = 50 options.
Now, we also know that there are 10 correct options and 40 incorrect ones.
The probability of selecting a correct option is 10/50 = 0.2
The probability of selecting an incorrect option is 40/50 = 0.8
We know that since he is selecting exactly 6 correct answers, there has to be 4 incorrect ones, since he's attempting 10 questions.
Applying this parameters in the equation yields the following :
(10C6) × (0.2)^6 × (0.8)^4 = 210 × 0.000064 × 0.4096 =0.005505024
This is approximately equal to 0.006
The answers in the options are in percentage. Hence we convert the decimal to percentage.
6/1000 × 100% = 0.6%
