Ta có:
\(B=\frac{13}{15}.0,25.3+\left(\frac{8}{15}-\frac{79}{60}\right):\frac{47}{24}\)
\(=\frac{13}{5}.\frac{1}{4}+\left(\frac{32}{60}-\frac{79}{60}\right).\frac{24}{47}\)
\(=\frac{13}{20}+\frac{-47}{60}.\frac{24}{47}\)
\(=\frac{13}{20}+\frac{-2}{5}=\frac{13}{20}+\frac{-8}{20}=\frac{5}{20}=\frac{1}{4}\)