Đáp án:
Giải thích các bước giải:
M=1/101+1/102+1/103+...+1/200
→M=(1/101+1/102+...+1/125)+(1/126+1/127+...+1/150)+(1/151+...+1/175)+(1/176+...+1/200)
→M>(1 /125+1/125+...+1/125)+(1/150+1/150+..+1/150)+(1/200+..+1/200)+(1/200+..+1/200)
→M>25/125+25/150+25/175+25/200
→M>1/5+1/6+1/7+1/8
→M>(1/5+1/6+1/7)+1/8
→M>107/210+1/8
→M>1/2+1/8=5/8
Vậy A=5/8