$\ A = \dfrac{8}{3.7} + \dfrac{8}{7.11} + \dfrac{8}{11.15} + ... + \dfrac{8}{97.101}$
$\ = 2(\dfrac{4}{3.7} +\dfrac{4}{7.11} + \dfrac{4}{11.15} +...+\dfrac{4}{97.101})$
`= 2(1/3 - 1/7 + 1/7 - 1/11 + 1/11 - 1/15 + ... + 1/97 - 1/101)`
`= 2(1/3 - 1/101)`
`= 2 . 98/303`
`= 196/303`
Vậy `A = 196/303`