Which is bigger : 30 or ?

30 can be written as 30/1 (I am including this information for the purpose of comparison). 30/1 has a larger numerator than its denominator which means that the, so its quotient will equal to more than 1.
However, 4/15 has a smaller numerator than its denominator, so 4 cannot be fully divided by 15. Therefore, the quotient will equal to less than 1.
This means that 30 is greater than 4/15.
(quick note: the quotient is the number you get from the division of two numbers)