Find the sum of all odd numbers between 100 and 200

the given sequence is 101, 103, ….199

Given an AP whose first term a is 101, and common difference d is 2


To find: the sum of all odd numbers between 100 and 200


Hence the sum is given by the formula


Substituting the values in the above equation we get



Now for the finding number of terms, the formula is




Substituting n is the sum formula we get



s = 25 × 300


s = 7500


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