Question

anurag saves rs 1 on day rs2 on day rs 3 on day an so on how much money will he save in the month of feb 2010

Answer 1

It becomes an A.P and as in feb 2010 no.of daus presnt are 28 no.of terms in a.pa are 28 so sum of n terms of an ap =n/2(2a+(n-1)d)
n=28,a=1,d=1 substiuting given values in formula we get answer as 406rs