`A=1/(2.5)+1/(5.8)+1/(8.11)+...+1/(92.95)+1/(95.98)`
`A=1/(3).((3)/(2.5)+3/(5.8)+3/(8.11)+...+3/(92.95)+3/(95.98))`
`A=1/(3).(1/2-1/5+1/5-1/8+1/8-1/(11)+..+1/(92)-1/(95)+1/(95)-1/(98))`
`A=1/(3).(1/2-1/(98))`
`A=1/(3).(24)/(49)`
`A=8/(49)`
Vậy `A=8/(49)`