The sum of the first 20 terms of the series 1/(5 × 6)+1/(6 × 7)+1/(7 × 8)+….. is · ABC26GN0737

Given expression $=\frac{1}{5 \times 6}+\frac{1}{6 \times 7}+\frac{1}{7 \times 8}+\ldots . .+\frac{1}{24 \times 25}$ $$\begin{aligned} & =\left(\frac{1}{5}-\frac{1}{6}\right)+\left(\frac{1}{6}-\frac{1}{7}\right)+\left(\frac{1}{7}-\frac{1}{8}\right)+\ldots .+\left(\frac{1}{24}-\frac{1}{25}\right) \\ & =\left(\frac{1}{5}-\frac{1}{25}\right)=\frac{4}{25}=0.16 . \end{aligned}$$