What is the approximate value will come in place of the question mark(?) in the following questions?

Direction : What should come in place of the question (?) in the following question.

12 × 3.5 – 8.5 × 3.2 =?

1, 3, 5, 7, ………total average of 25^th number  is:

The smallest number, which should be added to 756896 so as to obtain a multiple of 11, is :

While solving a problem, by mistake, Anita squared a number and then subtracted 25 from it rather than first subtracting 25 from the number and then squaring it. But she got the right answer. What was the given number? 

What should be added to $$ {10 \ over 11} $$ to get the sum $$ {11 \ over 10} $$?

4⁶¹ + 4⁶² + 4⁶³ + 4⁶⁴ is divisible by: 

The total number of integers between 100 and 200, which are divisible by both 9 and 6, is