Tính A/B : A = 1/99 + 2/98 + 3/97 +...+ 99/1. B = 1/2 + 1/3 + 1/4 +...+ 1/100

Bài 1:
A = 1/99 + 2/98 + 3/97 +...+ 99/1
B = 1/2 + 1/3 + 1/4 +...+ 1/100
TÍNH A/B
 Bài 2:
1/2 + 1/4 + 1/6 +...+ 1/998 + 1/1000/1/2. 1000 + 1 / 4.998 +...+ 1/998. 4 + 1/1000. 2
 Bài 3:
A = 1/1. 2 + 1/3. 4 + 1/5.6 +...+ 1/199. 200
B = 1/101. 200 + 1/102. 199 +...+ 1/200. 101