Question

Answer 1

`A = 1-5/6+7/12-9/20+11/30-13/42+15/56-17/72+19/90`

`A=1-(1/2+1/3)+(1/3+1/4)-(1/4+1/5)+(1/5+1/6)-(1/6+1/7)+(1/7+1/8)-(1/8+1/9)+(1/9+1/10)`

`A=1-1/2-1/3+1/3+1/4-1/4-1/5+1/5+1/6-1/6-1/7+1/7+1/8-1/8-1/9+1/9+1/10`

`A=1-1/2+1/10`

`A=10/10-5/10+1/10`

`A=6/10=3/5`