Three numbers in A P.with common difference `d (d!=1)` are removed from first natural numbers and average of remaining numbers are found to be `(43)/(4)` .Then `[(n+d)/(7)]` = (where [.] is G.I.F)

The S.D.of the first n natural numbers is

Three numbers in A.P are removed from first n consecutive natural numbers and average of remaining numbers is found to be 43/4 . Find n as well as removed numbers if one of the removed number is perfect square .

The S.D. of first n odd natural numbers is:

Three natural numbers in AP are removed from first 21 natural numbers. Mean of remaining numbers is 11. The sum of all common difference of all such possible increasing AP is.

In an A.P.if the common difference (d)=-4 and the seventh term (a_(7)) is 4 then find the first term

The first term a and common difference d are given. Find first four terms of A.P. a=200 , d=7

The first term a and common difference d are given. Find first four terms of A.P. a=-1 , d=-(1)/(2)

Two consecutive number from n natural numbers 1,2,3,……, n are removed. Arithmetic mean of the remaining numbers is (105)/(4). The value of n is:

Two consecutive number from n natural numbers 1,2,3,……, n are removed. Arithmetic mean of the remaining numbers is (105)/(4). The G.M. of the removed numbers is :

If the mean of first n natural numbers is (5n)/9 , then n= (a) 5 (b) 4 (c) 9 (d) 10