Let Sn be the sum of the first n terms of the arithmetic series 2+4+6+... . Find (i) S4 ; (ii) S100 .
(i) S4=2+4+6+8=20
(ii)S100= 2+4+...+200=2(1+2+...+100)=2(100+1)*(100/2)=10100
(i) S4=2+4+6+8=20
(ii)S100= 2+4+...+200=2(1+2+...+100)=2(100+1)*(100/2)=10100
