In an objective paper, there are two sections of 10 questions each.For "section 1", each question has 5 options and only one optionis correct and "section 2" has 4 options with multiple answers and marks for a question in this section is awarded only if he ticks all correct answers. Marks for each question in "sectionl 1" is 1 and in "section 2" is 3. (There is no negative marking.)
If a candidate attempts only two questions by guessing, one from "section 1" and one from "section 2", the probability that he scores in both question is `74/73`

Options

A. `(1//75)^(10)`
B. `1-(1//75)^(10)`
C. `(74//75)^(10)`
D. None of these

Answer

B

Explanation

To get 40 marks, he has to answer all questions correctly and its probability is `(1//5)^(10)(1//15)^(10).` Hence, probability of getting a score less than 40 is
`1-((1)/(5))^(10)((1)/(15))^(10)=1-((1)/(75))^(10)`