The following question is accompanied by two statements (I) and (II). You have to determine which statement(s) is/are sufficient/necessary to answer the questions.

A man borrowed a total sum of Rs. 2000 in two parts from a bank. For the first, he paid an interest of 12% p.a. and for other 6% p.a. How much money did he borrow at 6% p.a. rate? 

I. The sum of interests after 1 year was Rs. 192.

II. The interest on first part was thrice as compare to another.