Question

[ngô thị mai loan]

\(S=\frac{\frac{1}{2}+\frac{1}{3}+...+\frac{1}{200}}{\frac{1}{1999}+\frac{2}{1998}+...+\frac{198}{2}+\frac{199}{1}}\)       giải giúp mình với nhé

Answer 1

[Nguyễn Thị Thùy Dương]

\(M=1+\frac{1}{199}+1+\frac{2}{198}+1+....+\frac{198}{2}+1=\frac{200}{200}+\frac{200}{199}+\frac{200}{198}+....+\frac{200}{2}\)

  \(=200.\left(\frac{1}{200}+\frac{1}{199}+\frac{1}{198}+...+\frac{1}{2}\right)\)=200 T

\(S=\frac{T}{200T}=\frac{1}{200}\)