The sum of the series 1 + 1/2 + 1/22 + .......... is __________.
1
1/2
2
None of these
Sum of cubes of first n natural numbers is _______.
The 7th term of 1/3, 1/7, 1/11, ........... is ____________.
27
0
7/3
1/27
The harmonic mean between a and b is _________.
2ac / ( a + c )
( a + b ) / 2ab
√ab
( a + b ) / ab
The first term of an A.P is -1, and the C.D is -3 then 12th term is __________.
34
32
-32
-34
If x, y, z are in A.P, then 2y = ?
x + z
x - z
x / z
xz
There are n arithmetic means between a and b. Then the common difference d is _________.
( b + a ) / ( n + 1 )
( n + 1 ) / ( b + a )
( b - a ) / ( n + 1 )
ab / ( n + 1)
12 + 22 + 32 + ............ + 1002 = ?
5050
( 5050 )2
42925
The nth term of the series -3 + 6 - 12 + 24 - 48 .......... is _________.
( -1 )n * 3 * 2n-1
1n * 3 * 2n-1
3 * 2n+1
2 * 3n-1
The sum to n terms of 1, 8, 27, 64, ........ is ______.
