Arithmetic Progressions

IMPORTANT

Arithmetic Progressions: Overview

This topic covers concepts, such as, Arithmetic Progression (A.P.), Common Difference of an A.P., Mean & Arithmetic Mean (A.M.) of n Numbers etc.

Important Questions on Arithmetic Progressions

HARD
IMPORTANT

For each positive integer k , let S k denote the increasing arithmetic sequence of integers whose first term is 1 and whose common difference is k . For example,  S 3 is the sequence 1, 4, 7, 10 .............. . Find the number of values of k for which S k contain the term 361 .

HARD
IMPORTANT

 If   p,q,r are positive and are in A.P, and roots of the quadratic equation   p x 2 +qx+r=0 are real then 

EASY
IMPORTANT

In a triangle ABC, if tan(A/2),tan(B/2),tan(C/2) are in Arithmetic progression, then which of the following option is always correct?

EASY
IMPORTANT

The arithmetic mean of the following discrete data 12, 14, 20, 23, 25, 32 is given by

EASY
IMPORTANT

The arithmetic mean of five natural numbers is 40 . The largest exceeds the smallest number by 10 . If α is the maximum possible value for the largest of these 5 numbers, then the number of positive integral divisors of α is ______

EASY
IMPORTANT

The mean marks of 25 boys in a class is 61 and the mean marks of 35 girls in the same class is 58. Then the mean of all 60 students is

MEDIUM
IMPORTANT

The interior angles of a polygon are all obtuse and are in A.P. If the smallest angle is 120° and common difference of this A.P. is 5°, then the number of sides of the polygon is___________

EASY
IMPORTANT

If log32, log32x-5 and log32x-72 are in Arithmetic Progression, then the value of x is _________.

EASY
IMPORTANT

log102, log102x-1 and log102x+3 are three consecutive terms of an AP for

EASY
IMPORTANT

If a1, a2,a3. are terms of AP such that a1+a5+a10+a15+a20+a24=225, then the sum of first 24 terms is

MEDIUM
IMPORTANT

Let a1, a2, a3,  be an A.P. with a6=2 . Then the common difference of this A.P. , which maximize the product a1 a4 a5,  is :

EASY
IMPORTANT

The arithmetic mean of first n odd natural number is

EASY
IMPORTANT

If log2, log2n-1 and log2n+3 are in arithmetic progression, then the value of n will be

EASY
IMPORTANT

If r=1n2r+1=440 , then n=…..

MEDIUM
IMPORTANT

The coefficient of x49 in the product

x-1x-3...x-99  is

MEDIUM
IMPORTANT

If in an A.P, Sn=qn2 and Sm=qm2, where Sr denotes the sum of r terms of the A.P, then Sq equals

MEDIUM
IMPORTANT

The first three terms of a geometric sequence are x, y, z and these have the sum equal to 42. If the middle term y is multiplied by 5/4 , the numbers x, 5y4, z now form an arithmetic sequence. The largest possible value of x , is-

MEDIUM
IMPORTANT

If A.M. between pth and qth terms of an A.P. be equal to the A.M. between rth and sth terms of the A.P., then p+q is equal to

EASY
IMPORTANT

The sets S1,S2,S3 are given by S1=21, S2=32,52, S3=43,73,103, S4=54,94,134,174, Then, the sum of the numbers in the set S25 is

EASY
IMPORTANT

If a1, a2,a3, ......a24 are in A.P. such that a1+a5+a10 +a15+a20+a24 = 225. Then a1+a2+......+a24 is equal to