If 40% of a number is equal to 3 / 5th of another number, what will be the ratio of the first number and the second number?

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

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

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

Of the three numbers, the second is twice the first and it is also thrice the third. If the average of three numbers is 44, the difference of the first number and the third numbers 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 $$ {11 \ over 10} $$?

If (x¹¹+1) is divided by (x+1), then the remainder is :