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 three numbers a,b,c are in harmonic progression, then which of the following is true?
1/a, b, 1/c are in AP
1/bc, 1/ca, 1/ab are in HP
ab, bc, ca are in HP
a/b, b/c, c/a are in HP
If y = 1 + x + x2 + x3 + .... then x is equal to
y-1/y
1-y/y
y/a-y
None of these
If S is the sum of an infinite GP, the first term a, then the common ratio r is given by
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
3
5
9
8
The value of 91/3 × 91/9 × 91/27 × ...... is
1
If 2/3, k, 5/8 are in AP, then value of k is
15
21
12
31/48
is equal to
n
1/n
1/2 (n+n-1)
1/2 (en + e-n)
Fifth term of a GP is 2, then the product of its 9 terms is
256
512
1024
1100
If a, b, c be in arithmetic progression, then the value of (a+2 b - c) (2 b + c - a) (a + 2 b + c) is
16 a b c
4 a b c
8 a b c
3 a bc
