An online examination have 12 question out of which we have to solve three…
2025
An online examination have 12 question out of which we have to solve three questions. Choose how many ways can be there in which one can solve the question.
- A.
12C3
- B.
10C3
- C.
9C3
- D.
12C2
Attempted by 33 students.
Show answer & explanation
Correct answer: A
Key idea: We are choosing 3 questions out of 12 and the order of selection does not matter, so use combinations.
Step-by-step:
Use the combination formula: n choose k = n! ÷ (k! (n−k)!).
Here n = 12 and k = 3, so compute C(12,3) = 12! ÷ (3! × 9!).
Simplify by canceling 9!: C(12,3) = (12×11×10) ÷ (3×2×1).
Calculate: (12×11×10) ÷ 6 = 1320 ÷ 6 = 220.
Final answer: There are 220 ways to choose 3 questions from 12.