How many turns does the section of the double helix of DNA have that controls the synthesis of a protein with a molecular

How many turns does the section of the double helix of DNA have that controls the synthesis of a protein with a molecular weight of 30,000, if the molecular weight of one amino acid is on average 100, and there are 10 nucleotides per turn of the DNA helix?

1) the number of amino acids in the protein is 30,000: 100 = 300;
2) the number of nucleotides in DNA: 300 x 3 = 900;
3) the number of turns of the DNA helix: 900: 10 = 90.