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Find the modulo 7 remainder of the sum 1+3+5+7...+197+199

 Apr 17, 2018
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Find the modulo 7 remainder of the sum 1+3+5+7...+197+199

 

N = [199 -1] / 2 + 1 = 100 terms

S =[F + L] / 2 x N

S =[1 + 199] / 2 x 100 =10,000

Or: N^2 =100^2 =10,000

10,000 mod 7 = 4

 Apr 17, 2018
edited by Guest  Apr 17, 2018

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