Question

[do thu thao]

Cho C= \(\frac{1}{20}\)+ \(\frac{1}{21}\)+ \(\frac{1}{22}\)+ ... + \(\frac{1}{200}\)

CMR C > \(\frac{9}{10}\)

Answer 1

[❤℘ɦạℳ﹏Շɦị﹏Շɦų﹏ɦ¡ềท︵✰]

=> C > 1/200 + 1/200 + 1/200 + ...... + 1/200 ( 181 phân số )
=> C > 181/200 > 180/200 = 9/10
<=> C > 9/10