A person invests Rs.12000 as fixed deposit at a bank at the rate of 10% per annum simple interest. But due to some pressing needs he has to withdraw the entire money after 3 yr, for which the bank allowed him a lower rate of interest. If he gets Rs.3320 less than what he would have got at the end of 5 yr, the rate of interest allowed by the bank is :

• A. 7 (8/9)%
• B. 8 (7/9)%
• C. 7 (5/9)%
• D. 7 (4/9)%