JAMIA 2024 — Mathematics PYQ
JAMIA | Mathematics | 2024If nP3=4×nP2, find n.
Choose the correct answer:
- A.
3
- B.
2
- C.
6
(Correct Answer) - D.
5
6
Explanation
Step 1: Use the Permutation Formula
The formula for permutations is given by:
Applying this to both sides of the equation:
Step 2: Simplify the Factorials
We can expand the factorials to simplify the expression:
-
(n−3)!n!=n(n−1)(n−2)
-
(n−2)!n!=n(n−1)
Now, substitute these back into the equation:
Step 3: Solve for n
Since n≥3 (for nP3 to be defined), we know that n=0 and n=1. Therefore, we can divide both sides by n(n−1):
Adding 2 to both sides:
Final Answer
The value of n is:
Explanation
Step 1: Use the Permutation Formula
The formula for permutations is given by:
Applying this to both sides of the equation:
Step 2: Simplify the Factorials
We can expand the factorials to simplify the expression:
-
(n−3)!n!=n(n−1)(n−2)
-
(n−2)!n!=n(n−1)
Now, substitute these back into the equation:
Step 3: Solve for n
Since n≥3 (for nP3 to be defined), we know that n=0 and n=1. Therefore, we can divide both sides by n(n−1):
Adding 2 to both sides:
Final Answer
The value of n is:

