Question

[Ototo No]

Cho S= 1/ 51 + 1/ 52 +... + 1/60

So sánh S với 1/ 2

Answer 1

[Lương Khánh Ngọc]

mk cx k chắc lắm nha

Ta có1/51<1/50  ,  1/52<1/50......1/60<1/50

=>1/51+1/51+...+1/60< 1/50.10

=>1/51+1/51+...+1/60<1/5   ,1/5<1/2

=> 1/51+1/51+...+1/60<1/2

=>S<1/2