Please solve this problem

This query is : Resolved

Querist : Anonymous

Querist : Anonymous (Querist)

06 September 2011 1).a person pays Rs.975 by monthly instalment each less then the former by Rs.5.the first instalment is Rs.100.the time by which the entire amount will be paid is?
answer:15months.
2).a person solved Rs.16500 in ten years.in each year after the first year he saved Rs.100 more than he did in the preceeding year.the amount of money he saved in the 1st year was?
answer:Rs.1200.
3).if the sum of first n terms of an a.p is 2n^2+n then the difference of its tenth & first term is?
answer:36
4).g is g.m.between a & b then 1/g^2-a^2+1/g^2-b^2=?
answer:1/g^2