@ nikita
WHAT EXACTLY U WANT TO KNOW ??
i am sorry there is no attachment in the question , kindly attach the ques in which u have problems .
and the most imp topics in that chap is sum of n terms and finding the g.p from that .
for more detauils , check out askiitians study material .
WAITING TO HEAR FROM YOU AGAIN WITH THE QUESTION
ALL THE BEST ..