when 0<=x<1/n why x=0.can't be x a number between 1/n and 0?

Answer 1

0 <= x < 1/n

This statement says that X is greater that or equal to zero but less than 1/n.

So any number greater that 0 but less than 1/n could be X. To meet these requirements however, n must be a positive number or else X could not meet both tests. For example, X cannot be both greater that 0 and less than 1/-3.

Answer 2

If x = 0, how can it be "between" 1/n and 0 ?

Answer 3

if the inequality had been 1/n<=x<=0
then x will be between 1/n and 0
howener if n is positive it does not
make any difference either way