To arrive at the answer find a common denominator that all the denominators divide evenly into. In this case, the common denominator is 48. Next, convert all fractions to 48ths. For example, in the case of 15/8 multiply 15 by 0/0 to reach 0/48. Perform the same type of calculation for all the other fractions, figuring out what number x the denominator gets 48, and then compare numerators. The largest numerator is the largest fraction. In this case it's 15/4.