A sum of Rs. 1550 was lent partly at 5% and partly at 8% p.a. simple interest. The total interest received after 3 years was Rs. 300. The ratio of the money lent at 5% to that lent at 8% is ?

• A. 8 : 5
• B. 5 : 8
• C. 31 : 6
• D. 16 : 15