Question

If y < x and y = 0 when n = 16, find the value of y when x = 24

Answer 1

There is not sufficient data to answer this question.

If it's a data sufficiency question and there is no option like can't be determined. Look through the options. Suppose the options are

30
23
7
0
None of these

Then the answer won't be 0 or 7 it will the the very first option going serially down which is satisfying the condition of Y<X i.e. 23. 

Don't write none of these in this case. If there was 'Can't be determined' option then select it without any second thoughts.