A man took a loan at rate of 12% per annum simple interest. After 3 years he had to pay 4320 interest. The principal amount borrowed by him was.
Choose the correct answer.
A) rs 14000  B) rs 15000  C) rs 12000  D) rs 17000  E) none of these

Rationale: "explanation : s . i . = p â ˆ — r â ˆ — t / 100 = > p = s . i . â ˆ — 100 / r â ˆ — t = > p = 4320 â ˆ — 100 / 12 â ˆ — 3 = rs 12000 option c"
Answer: C