If x = 1 + 2 + 4/2! + 8/3! + 16/4! + ...., then x-1 is equal to
e-2
e2
e1/2
None of these
The value of 91/3 × 91/9 × 91/27 × ...... is
9
3
1
Let a be a positive number such that the arithmetic mean of a and 2 exceeds their geometric mean by 1. Then, the value of a is
5
8
If S is the sum of an infinite GP, the first term a, then the common ratio r is given by
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
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
n
3 n
The value of is
log 3
log 2
1/2
In a geometric progression consisting of positive terms, each term equals the sum of the next two terms. Then the common ratio of this progression equals.
1/2 (1- √5)
1/2 √5
√5
1/2 (√5 -1)
Geometric mean of 7,72,73,....7n is
7
7n/2
7n
