Solution:We will first identify the formula for calculating the total interest.
S.I. for n month
S.I. for 1 month
S.I. for n-1 months
We know that,
Total amount Deposited= Monthly deposit
Maturity Value= Rs.12,440
We have the formula,
Substituting the above values in the formula we get
Maturity Value= Total Deposited Amount + Total Simple Interest.
To simplify the equation we can divide it throughout by 4.
On factorization we will get,
Now, n is no months which cannot be negative.
Therefore, the acceptable value of n is 10.
So, option 3 is correct.