Tính :

Tính :
C = 1/2 + ( 1/3 + 2/3 ) + ( 1/4 + 2/4 + 3/4 ) + ( 1/5 + 2/5 + 3/5 + 4/5 ) + ...... + ( 1/100 + 2/100 + 3/100 + 4/100 +....... + 99/100 )