A. 1, 5x, 11x2
B. 1, 10x, 15x2
C. 1,10x, 55x2
D. 1, 15x, 50x2
C0+4.C1+7.C2+……(n+1) terms =
The number of terms which are free from radical signs in the expansion of (x1/5+y1/10)55 is
If the third term in the expansion of (1/x+ xlog10 x)5 is 1, then x=
2.C0+22.C1/2+23.C3/3+……..+2n+1.Cn/n+1 =
If n is odd then C02-C12+C22-……….+(-1)n Cn2 =
Coefficient of x50 in (1+x)1000+2x(1+x)999+3x2(1+x)998+……..+1001x1000 is
The midpoint of the line segment joining (2,3,-1), (4,5,3) is
The coefficient of x6 in (1+x+x2+x3+x4+x5)6 is
The ratio of the coefficient of x15 to the term independent of x in (x2+2/x)15 is
The number of non zero terms in the expansion of (a+b)20 – (a-b)20 is