Question
Wed November 21, 2012 By: Pawan Chhipa
 

SIR,students save Rs5(in first day)Rs10,Rs15......... what will be his collection in february 2013.

Expert Reply
Thu November 22, 2012
The sequence of savings
5, 10, 15, ...
form an AP with:
First term = a = 5
Common difference = d = 5
 
In February 2013, there are 28 days.
So, to find the collection in this month, we need to calculate the sum of 28 terms of an AP which can be calcuated by using the following formula:
Sn = S28 = (n/2)*[2a+ (n-1)d]
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