If y = 1 + x + x2 + x3 + .... then x is equal to
y-1/y
1-y/y
y/a-y
None of these
is equal to
n
1/n
1/2 (n+n-1)
1/2 (en + e-n)
The 5th term of the series is
1/3
1
2/5
The sum to infinity of the progression 9 - 3 + 1 -1/3 + .... is
9
9/2
27/4
15/2
The value of 91/3 × 91/9 × 91/27 × ...... is
3
If 2/3, k, 5/8 are in AP, then value of k is
15
21
12
31/48
In an AP the sum of any two terms, such that the distance of one of them from the beginning is same as that of the other from the end, is
first term
sum of first and last terms
last term
half of the sum of the series
In an arithmetic progression, the 24th term is 100. Then, the sum of the first 47 terms of the arithmetic progression is
2300
2350
2400
4700
If twice the 11th terms of an AP is equal to 7 times its 21st term, then its 25th term is equal to.
24
120
0
The arithmetic means of first n odd natural number is
n2
2 n
3 n
