security deposits are the amount of money that the landlords are supposed to acquire from tenants in advance while renting out the property as to protect against non-payment.
At the natural time of expiry of the contract between the landlord and tenants the security deposits can be utilized by the landlords for following causes:
From September 20 to January 20, there are 4 months only which is equivalent to 1/3 of a year. The interest earned by the investment, P, made is calculated