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Each of the questions given below consists of two statements numbered I and II given below it. Please read the questions carefully and decide whether the data provided in the statement(s) is / are sufficient to answer the given question.

1)

What was the total compound interest on a sum after 3 years ?

I. The interest after one year was Rs. 100 and the sum was Rs. 1000.
II. The difference between simple and compound interest on a sum of Rs. 1000 at the end of 2 years was Rs. 10.


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

Answer:

Option C

Explanation:

I. gives : P = Rs. 1000 and S.I for 1 year = Rs. 100.

Rate =100×S.I.P×T

=100×1001000×1 =10% p.a.

Thus, P = Rs. 1000,T=3 years and R=10 p.a.

C.I. may be obtained.

II. Sum = Rs. 1000,(C.I.)(S.I.) for 2 years = Rs. 10.

Let the rate be R% p.a.

1000×[(1+R100)21] (1000×R×2100) =10.

From this, we can find R.

Thus P, T and R are given and therefore, C.I may be calculated.

Thus, I alone as well as II alone is sufficient to get the answer.

Correct answer is (C).