Compound Interest - General Aptitude

Each of the questions given below consists of a statement and / or a question and two statements numbered I and II given below it. You have to decide whether the data provided in the statement(s) is / are sufficient to answer the given question. Read the both statements and
  • Give answer (A) if the data in Statement I alone are sufficient to answer the question, while the data in Statement II alone are not sufficient to answer the question.
  • Give answer (B) if the data in Statement II alone are sufficient to answer the question, while the data in Statement I alone are not sufficient to answer the question.
  • Give answer (C) if the data either in Statement I or in Statement II alone are sufficient to answer the question.
  • Give answer (D) if the data even in both Statements I and II together are not sufficient to answer the question.
  • Give answer(E) if the data in both Statements I and II together are necessary to answer the question.
Q1:

What is the rate of compound interest?  I. The principal was invested for 4 years.  II. The earned interest was Rs. 1491.

A I alone sufficient while II alone not sufficient to answer

B II alone sufficient while I alone not sufficient to answer

C Either I or II alone sufficient to answer

D Both I and II are not sufficient to answer

E Both I and II are necessary to answer

ANS:D - Both I and II are not sufficient to answer

Let Principal = Rs. P and Rate = R% p.a. Then,

Amount = Rs. P 1 + R 4
100
 C.I. = P 1 + R 4 - 1
100
P 1 + R 4 - 1 = 1491.
100
Clearly, it does not give the answer.  Correct answer is (D).