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If nC(r-1)=56 nCr=28 and nC(r 1)=8 then r is equal to?
Most Upvoted Answer
If nC(r-1)=56 nCr=28 and nC(r 1)=8 then r is equal to?
Explanation:
Step 1: Use the formula of combination nCr = n!/r!(n-r)!
nC(r-1)=56 can be written as n!/(r-1)!(n-r+1)!=56
nCr=28 can be written as n!/r!(n-r)!=28
nC(r+1)=8 can be written as n!/(r+1)!(n-r-1)!=8
Step 2: Use the value of nCr to find n.
n!/r!(n-r)!=28
56/(r-1)!=28
(r-1)!=2
r-1=2
r=3
Substitute the value of r in other equations to find n.
n!/(r+1)!(n-r-1)!=8
n!/4(n-2)!=8
n!/n(n-1)(n-2)/24=8
n(n-1)(n-2)/3!=6
n(n-1)(n-2)=6*3!
n(n-1)(n-2)=36
n=6
n!/r!(n-r)!=28
6!/3!(6-3)!=28
20=28
Step 3: Check if nC(r+1) is correct.
nC(r+1)=8
6C4=15
Hence, the value of nC(r+1) is not correct.
Therefore, there is no solution to this problem with the given information.
Step 1: Use the formula of combination nCr = n!/r!(n-r)!
nC(r-1)=56 can be written as n!/(r-1)!(n-r+1)!=56
nCr=28 can be written as n!/r!(n-r)!=28
nC(r+1)=8 can be written as n!/(r+1)!(n-r-1)!=8
Step 2: Use the value of nCr to find n.
n!/r!(n-r)!=28
56/(r-1)!=28
(r-1)!=2
r-1=2
r=3
Substitute the value of r in other equations to find n.
n!/(r+1)!(n-r-1)!=8
n!/4(n-2)!=8
n!/n(n-1)(n-2)/24=8
n(n-1)(n-2)/3!=6
n(n-1)(n-2)=6*3!
n(n-1)(n-2)=36
n=6
n!/r!(n-r)!=28
6!/3!(6-3)!=28
20=28
Step 3: Check if nC(r+1) is correct.
nC(r+1)=8
6C4=15
Hence, the value of nC(r+1) is not correct.
Therefore, there is no solution to this problem with the given information.
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If nC(r-1)=56 nCr=28 and nC(r 1)=8 then r is equal to?
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If nC(r-1)=56 nCr=28 and nC(r 1)=8 then r is equal to? for CA Foundation 2024 is part of CA Foundation preparation. The Question and answers have been prepared according to the CA Foundation exam syllabus. Information about If nC(r-1)=56 nCr=28 and nC(r 1)=8 then r is equal to? covers all topics & solutions for CA Foundation 2024 Exam. Find important definitions, questions, meanings, examples, exercises and tests below for If nC(r-1)=56 nCr=28 and nC(r 1)=8 then r is equal to?.
If nC(r-1)=56 nCr=28 and nC(r 1)=8 then r is equal to? for CA Foundation 2024 is part of CA Foundation preparation. The Question and answers have been prepared according to the CA Foundation exam syllabus. Information about If nC(r-1)=56 nCr=28 and nC(r 1)=8 then r is equal to? covers all topics & solutions for CA Foundation 2024 Exam. Find important definitions, questions, meanings, examples, exercises and tests below for If nC(r-1)=56 nCr=28 and nC(r 1)=8 then r is equal to?.
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