Question:
There are 3 sections in a question paper and each section contains 5 questions. A candidate has to answer a total of 5 questions, choosing at least one question from each section. Then the number of ways, in which the candidate can choose the questions, is:
Correct Option: , 4
Solution:
(4) Since, each section has 5 questions.
$\therefore$ Total number of selection of 5 questions
$=3 \times{ }^{5} C_{1} \times{ }^{5} C_{1} \times{ }^{5} C_{3}+3 \times{ }^{5} C_{1} \times{ }^{5} C_{2} \times{ }^{5} C_{2}$
$=3 \times 5 \times 5 \times 10+3 \times 5 \times 10 \times 10$
$=750+1500=2250$