Odd numbers add and subtract equal to 32 Among all odd numbers from 1 to 31, select 7 digits to add and subtract (the number can be reused), and the result is 32

Odd numbers add and subtract equal to 32 Among all odd numbers from 1 to 31, select 7 digits to add and subtract (the number can be reused), and the result is 32

impossible
Add and subtract 7 odd numbers, the result is odd, not even

What is the result of 1 + 2 + 3 + 4 + 5 + 6 +. + 1999 + 2000 + 2001 +. 2006? Odd or even?

1 + 2 + 3 + 4 + 5 + 6 +. + 1999 + 2000 + 2001 +. 2006 according to the arithmetic sequence summation formula, the original formula = 1 / 2 * (1 + 2006) * 2006 = 2 013 021, the last is odd, because there are 1003 odd numbers in it, and the sum must be odd! You see, do you understand? If not, I'll explain again! The most important thing is the method, the method