SOLUTION: What is the difference between the sum of all postive odd integers less than 102 and the sum of all positive even integers less than 102 ?

 
The other tutor's answer is incorrect.  

The first 101 integers consist of 50 even numbers and 51 odd numbers

sum of odds  = 1 + 3 + 5 + 7 + ··· + 95 + 97 + 99 + 101
sum of evens =     2 + 4 + 6 + ··· + 94 + 96 + 98 + 100
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difference   = 1 + 1 + 1 + 1 + ··· +  1 +  1 +  1 +   1

When we subtracted them above, term by term, there is a 1 
in each of the positions of the 51 odd numbers. The sum of 
51 1's is 51.

Answer: 51

Edwin