\(B=\left(1+\dfrac{1}{2}\right)\times\left(1+\dfrac{1}{3}\right)\times\left(1+\dfrac{1}{4}\right)\times...\times\left(1+\dfrac{1}{10}\right)\)
\(B=\dfrac{3}{2}\times\dfrac{4}{3}\times\dfrac{5}{4}\times...\times\dfrac{11}{10}\)
\(B=\dfrac{11}{2}\)
Vậy \(B=\dfrac{11}{2}\).
\(B=\left(1+\dfrac{1}{2}\right)\left(1+\dfrac{1}{3}\right)\left(1+\dfrac{1}{4}\right)....\left(1+\dfrac{1}{10}\right)\)
\(=\dfrac{3}{2}\cdot\dfrac{4}{3}\cdot\dfrac{5}{4}\cdot\cdot\cdot\cdot\dfrac{11}{10}\\ =\dfrac{3\cdot4\cdot5...11}{2\cdot3\cdot4...10}=\dfrac{11}{2}\)