`#Mon`
`@A=\frac{2}{1xx4}+\frac{2}{4xx7}+\frac{2}{7xx10}+\frac{2}{100xx103}`
`=\frac{3}{3}xx(\frac{2}{1xx4}+\frac{2}{4xx7}+\frac{2}{7xx10}+\frac{2}{100xx103})`
`=\frac{2}{3}xx(\frac{3}{1xx4}+\frac{3}{4xx7}+\frac{3}{7xx10}+\frac{3}{100xx103})`
`=\frac{2}{3}xx(1-\frac{1}{4}+\frac{1}{4}-\frac{1}{7}+...+\frac{1}{100}-\frac{1}{103})`
`=\frac{2}{3}xx[1+(-\frac{1}{4}+\frac{1}{4}+(-\frac{1}{7}+\frac{1}{7})+...+(-\frac{1}{100}+\frac{1}{100})-\frac{1}{103}]`
`=\frac{2}{3}xx[1+(-\frac{1}{103}]`
`=\frac{2}{3}xx(1-\frac{1}{103})`
`=\frac{2}{3}xx\frac{102}{103}`
`=\frac{204}{309}`
`=\frac{68}{103}`
