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If the average of the first 'n' numbers in the sequence 148,146,144..., is 125, then n=


Omprasad Kuruma 30th Sep, 2018
Answer (1)
Vikas gehlot 2nd Oct, 2018

This is an Arithmetic Progression with common difference of -2.

Now using the sum of first n terms we get.

(2a+(n-1)d)=250

Here a=148 and d=-2

So we have

(296-2(n-1))=250

2(n-1)=46

n-1=23

n=24

This is the Required Value of n;

Here we have used the formula for the sum of AP.


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