4 12 8. 15 2-1 37 If 15P = 32760, then r= 1) 4 25 36 Ifnp = 5040 then (n,r) = 4) 7 20. The number all the lette the vowels

If "^15P_r : "^16P_r = 3:4 then r =

If P(15 ,r-1): P(16 ,r-2)=3:4 , find rdot

15P_(r-1):^(15)P_(r-2)=3:4, then r=

If nC_(r-1)=36,nC_(r)=84 and nC_(r+1)=126 then (a) n=8,r=4( b) n=9,r=3(c)n=7,r=5(d) non of these

If N_(1) is the number of arrangements of the letters of the word 'EQUATION' in which all vowels are together and N_(2) is the number of arrangements of the letters of the word 'PERMUTATION' in which vowels are in alphabetical order, then (4N_(2))/(7N_(1))=

IF ""^(15)P_(r-1):""^(16)P_(r-2) = 3 : 4 then r=

If .^(15)C_(2r-1) = .^(15)C_(2r + 4) " find " r

If P(15,r-1):P(16,r-2)=3:4, find r.

Evaluate (n!)/(r!(n-r)!) , where n=15,r=4

Evaluate (n!)/(r!(n-r)!) , where n=15,r=4