+0  
 
0
54
1
avatar

Find the modulo 7 remainder of the sum 1+3+5+7...+197+199+201.

 Nov 17, 2020
 #1
avatar+114221 
+1

We can find the  number of odd positive  terms by

 

2n  - 1  = 201

2n = 202

n =101

 

And the  sum of the  first  n  odd positive  terms  = n^2  = 101^2  = 10201

 

So

 

10201  mod 7   =     2

 

 

 

 

 

cool cool cool cool  

 Nov 17, 2020

17 Online Users

avatar