The present worth of Rs. 2310 due 2 years hence, the rate of interest being 15% per annum, is:  Choose the correct answer:
A) 1689
B) 1680
C) 1682
D) 1681
E) 1686

Rationale: "p . w . = rs . 100 x 2310 = rs . 1680 . 100 + 15 x 5 2 answer : b"
Answer: B