MEDIUM
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If i=1nCi-1nCin+Ci-1n3=3613 then n is equal to

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Important Questions on Binomial Theorem

MEDIUM
The number of ordered pairs r,k for which 6·Cr35=k2-3·Cr+136, where k is an integer is
HARD
If i=120 20Ci-1 20Ci+20Ci-13=k21, then k equals
HARD
Suppose detk=0nkk=0nCk nk2k=0nCk nkk=0nCk n3k=0, holds for some positive integer n. Then k=0nCk nk+1 equals
EASY
If c0, c1, c2,,., c15 are the binomial coefficients in the expansion of (1+x)15, then the value of c1c0+2c2c1+3c3c2++15c15c14 is
MEDIUM
The value of r=110r·CrnCr-1n is equal to
HARD
Sum of last 30 coefficents in the binomial expansion of 1+x59 is
MEDIUM
The number of selection of n objects from 2n objects of which n are identical and the rest are different, is
MEDIUM
In order to get through in an examination of nine papers, a candidate has to pass in more papers than the number of papers in which he fails. The number of ways in which he can fail, in this examination is
EASY
If (2rn), then Crn+2·Cr+1n+Cr+2n is equal to
EASY
Total number of 6-digit numbers in which only and all the five digits 1,3,5,7 and 9 appears, is
EASY
For 2rn,Crn+2Cr-1n+Cr-2n is equal to
MEDIUM
The value of r=020C650-r is equal to:
MEDIUM
If Cr-1n=10,Crn=45 and Cr+1n=120, then r equals
HARD
If in a regular polygon the number of diagonals is 54, then the number of sides of this polygon is:
HARD
If x=C516+C412, y=r=13C420-r, z=k=14C316-k, then x+y+z=
MEDIUM
Let (1+x)n=C0+C1x+C2x2++Cnxn, where Cr=Crn and C0+C1C1+C2Cn-1+Cn=AC1C2Cn, then for n=5, A is equal to
EASY

In how many ways a team of 5 members can be chosen from 8 members?

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From 6 different novels and 3 different dictionaries, 4 novels and 1 dictionary are to be selected and arranged in a row on the shelf so that the dictionary is always in the middle. Then the number of such arrangement is