So to begin, you need to know the least common denominator for 1/4 and 3/20. What do 20 and 4 have in common? 20. So Now you have 3/20 and 1/20. The 1 in 1/20 needs to be multiplied by 5. The reason behind this is because you have to multiply the denominator by 5 to get /20. Now you have 3/20 and 5/20. So, the 1/4 or 5/20 option is greater than 3/20.