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TS EAMCET · Maths · Permutation Combination

The number of values of n for which C2n+2:C1n+3=4:2 is

  1. A 0
  2. B 1
  3. C 2
  4. D 3
Verified Solution

Answer & Solution

Correct Answer

(A) 0

Step-by-step Solution

Detailed explanation

Given that n∈N C2 n+2: C1n+3=4:2 we know that Crn =n!(n-r)!r! ⇒(n+2)!(n+2-2)!2!×(n+3-1)!1!(n+3)!=42 ⇒(n+2)!n! 2!×(n+2)!(n+3)(n+2)!=42 ⇐(n+2)(n+1)n!n! 2! (n+3)=42 ⇒n2+3n+2=4n+3(4) ⇒n2-n-10=0…