the sum of the first 100 terms common to these series 17,21,25........and 16,21,26,.........is- (a)101100 (b)111000 (c)110010 (d)100101

Asked by paritosh jain | 17th Oct, 2012, 05:10: PM

Expert Answer:

The first term common to each of the series is 21.

The common difference of first series (a) is 4 and the common difference of the second series is 5.

 

Therefore, the common difference of the common series (d) to both of these series is LCM of 4 and 5 = 20.

 

Now, sum of 100 terms to common of these series;

 
The correct answer is (a)

Answered by  | 17th Oct, 2012, 09:28: PM

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