JAMIA 2024 — Mathematics PYQ
JAMIA | Mathematics | 2024nPr=nCrx
Choose the correct answer:
- A.
r!
(Correct Answer) - B.
1/r!
- C.
n!
- D.
1/n!
r!
Explanation
Step 1: Write the Formulas
The formula for Permutations is:
nPr=(n−r)!n!
The formula for Combinations is:
nCr=r!(n−r)!n!
Step 2: Relationship between P and C
We can rewrite the combination formula to show its relationship with the permutation formula:
nCr=r!1×((n−r)!n!)
nCr=r!nPr
Step 3: Solve for x
The given equation is:
nPr=nCr⋅x
Substitute the relationship nPr=r!⋅nCr into the equation:
r!⋅nCr=nCr⋅x
Dividing both sides by nCr:
x=r!
Final Answer
The value of x is:
r!
Explanation
Step 1: Write the Formulas
The formula for Permutations is:
nPr=(n−r)!n!
The formula for Combinations is:
nCr=r!(n−r)!n!
Step 2: Relationship between P and C
We can rewrite the combination formula to show its relationship with the permutation formula:
nCr=r!1×((n−r)!n!)
nCr=r!nPr
Step 3: Solve for x
The given equation is:
nPr=nCr⋅x
Substitute the relationship nPr=r!⋅nCr into the equation:
r!⋅nCr=nCr⋅x
Dividing both sides by nCr:
x=r!
Final Answer
The value of x is:
r!

