The complete question is:
What would be the minimum codon size (number of nucleotides) required to specify all amino acids if the number of different types of amino acids in proteins were: (1) 2, (2) 8, (3) 17, (4) 45, (5) 75?
Answers:
1) 1
2) 2
3) 3
4) 3
5) 4
These calculation take into account:
Available bases^ codon size
(* nucleotides)=* possible codons