You are provided with 20 different amino acids to construct a polypeptide chain containing 100 amino acid residues. How many different polypeptide chains can be constructed ?

Number of different amino acids available to be included in the polypeptide chain=x;Number of  amino acids in each polypeptide chain=y;Possible polypeptide chains=xy;Thus from the given data, possible polypeptide chains=20100