\(B=\frac{5}{2.1}+\frac{4}{1.11}+\frac{3}{11.2}+\frac{1}{2.15}+\frac{13}{15.4}\)
\(B=\frac{5}{2}+\frac{4}{11}+\frac{3}{22}+\frac{1}{30}+\frac{13}{60}\)
\(B=\left(\frac{5}{2}+\frac{4}{11}+\frac{3}{22}\right)+\left(\frac{1}{30}+\frac{13}{60}\right)\)
\(B=\frac{66}{22}+\frac{15}{60}\)
\(B=3+\frac{1}{4}\)
\(B=\frac{13}{4}\)