If the simple interest on a certain amount in at 4% rate 5 years amounted to Rs 1920 less than the principal. What was the principal? Pick one:
A) 1500 B) 2500 C) 2507 D) 3200 E) 2400

Rationale: "p - 1920 = ( p * 5 * 4 ) / 100 p = 2400 answer : e"
Answer: E