a=x I
b=x+5\frac{11}{15} II
c=x+5\frac{11}{15}+5\frac{11}{15}=x+10\frac{22}{15}=x+11\frac{7}{15} III
a+b=14\frac{12}{15}
x+x+5\frac{11}{15}=14\frac{12}{15}
2x+5\frac{11}{15}=14\frac{12}{15}
2x=14\frac{12}{15}-5\frac{11}{15}
2x=9\frac{1}{15}
x=9\frac{1}{15}:2=9\frac{1}{15}*\frac{1}{2}=\frac{136}{15}*\frac{1}{2}=\frac{136}{30}=4\frac{16}{30}=4\frac{8}{15}=a
b=x+5\frac{11}{15}=4\frac{8}{15}+5\frac{11}{15}=9\frac{19}{15}=10\frac{4}{15}
a+b+c=30\frac{12}{15}
c=30\frac{12}{15}-(a+b)=30\frac{12}{15}-(4\frac{8}{15}+10\frac{4}{15})=30\frac{12}{15}-14\frac{12}{15}=16