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 b c
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
The arithmetic means of first n odd natural number is
n2
2 n
n
3 n
Geometric mean of 7,72,73,....7n is
7
7n/2
7n
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
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
The 5th term of the series is
1/3
1
2/5
The sum of the integers from 1 to 100 which are divisible by 3 and 5 is
2317
2632
315
2489
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 sum to infinity of the progression 9 - 3 + 1 -1/3 + .... is
9/2
27/4
15/2
