Question

Determine S9 of the series where a=6 and r=2

Answer 1

Hi

arithmetic serie mean that to change from a rank to an other, you add "r"

So : if 6 is S1, and 2 is pace,

then you need 8 hops to go from S1 to S9.

so you 'r going to add the reason 8 times.

so : S9 = 6 + 8 * 2 = 6 + 16 = 22

conclusion : S9 = 22