Đáp án:
`A=99`
Giải thích các bước giải:
`A=50+ 50/3+25/3+20/4+10/3+100/6.7+...+100/98.99+1/99`
`A=100/2+100/6+100/12+100/20+100/30+100/6.7+...+100/98.99+100/99.100`
`A=100/1.2+100/2.3+100/3.4+100/4.5+100/5.6+100/6.7+...+100/98.99+100/99.100`
`A/100=1/1.2+1/2.3+1/3.4+1/4.5+1/5.6+1/6.7+...+1/98.99+100/99.100`
`A/100=1-1/2+1/2-1/3+1/3-1/4+1/4-1/5+1/5-1/6+1/6-1/7+...+1/98-1/99+1/99-1/100`
`A/100=1-1/100`
`A=100(1-1/100)`
`A=100-1`
`A=99`
Vậy `A=99`.
