Display Five-bit Binary Numbers in Decimal?

I'm so confused how to display a 5 variable binary kmap to hexadecimal display. How would you do a kmap without being given a function? Just put random functions on it? Also, how would you implement it just by using and,nand,or, not chips? Confused...please clarify and teach me.|||You need to create a 4-bit units digit signal from 0 to 9 and a 2-bit tens digit signal from 0 - 3 from the 5 bits that you start with. You need to figure out the details of the function as part of the problem.