3/(2*5)+3/(5*8)+3/(8*11)+…… +3/(1994*1997*) 1 and 1 / (3 * 5) + 2 and 1 / (5 * 7) + 3 and / (7 * 9) + +100 and 1 / (201 * 203) 1/(1*3)+1/(3*5)+1/(5*7)+…… +1/(97*99)+1/(99*101) I already can You did something wrong

3/(2*5)+3/(5*8)+3/(8*11)+…… +3/(1994*1997*) 1 and 1 / (3 * 5) + 2 and 1 / (5 * 7) + 3 and / (7 * 9) + +100 and 1 / (201 * 203) 1/(1*3)+1/(3*5)+1/(5*7)+…… +1/(97*99)+1/(99*101) I already can You did something wrong

first
=1/2-1/5+1/5-1/8+1/8-1/11…… -1/1997
=665/1332
the second
=1+2+3.+100+(1-1/3+1/3-1/5.-1/203)/2
=5050 and 101 / 203
The third one is the same as the second one