Simple Interest

What is the principal sum?
I.	The sum amounts to Rs. 690 in 3 years at S.I.
II.	The sum amounts to Rs. 750 in 5 years at S.I.
III.	The rate of interest is 5% p.a.

A:

I and III only

B:

II and III only

C:

I and II only

D:

I and III only, or II and III only

Answer: E

Clearly, any two of the three will give us the answer.

Correct answer is (E).

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What is the rate of simple interest?
I.	The total interest earned was Rs. 4000.
II.	The sum was invested for 4 years.

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

Answer: D

We know that, R =		100 x S.I.
		P x T

Now, I gives, S.I. = Rs. 4000.

II gives, T = 4 years.

But, P is unknown. So, we cannot find R.

So, given data is insufficient to get R.

Correct answer is (D).

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What percentage of simple interest per annum did Anand pay to Deepak?
I.	Anand borrowed Rs. 8000 from Deepak for four years.
II.	Anand returned Rs. 8800 to Deepak at the end of two years and settled the loan.

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

Answer: E

Let the rate be R% p.a.

I gives, P = Rs. 8000 and T = 4 years.

II gives, S.I. = Rs. (8800 - 8000) = Rs. 800.

R =		100 x S.I.		=		100 x 800	%	= 2	1	% p.a.
		P x T				8000 x 4			2

Thus, I and II both are needed to get the answer.

Correct answer is (E).

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What is the sum which earned interest?
I.	The total simple interest was Rs. 7000 after 7 years.
II.	The total of sum and simple interest was double of the sum after 5 years.

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

Answer: E

Let the sum be Rs. x.

I gives, S.I. = Rs. 7000 and T = 7 years.

II gives, Sum + S.I. for 5 years = 2 x Sum Sum = S.I. for 5 years.

Now, S.I. for 7 years = Rs. 7000.

S.I. for 1 year = Rs.	7000	= Rs. 1000.
	7

Thus, I and II both are needed to get the answer.

Correct answer is (E).

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The simple interest on a sum of money is Rs. 50. What is the sum?
I.	The interest rate is 10% p.a.
II.	The sum earned simple interest in 10 years.

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

Answer: E

Given : S.I. = Rs. 50.

I gives, R = 10% p.a.

II gives, T = 10 years.

Sum =		100 x S.I.		= Rs.		100 x 50		= Rs. 50.
		T x R				10 x 10

Thus, I and II together give the answer.

Correct answer is (E).

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Questions for: Simple Interest