What is the rate of interest p.c.p.a.? I. An amount doubles itself in 5 years on

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Home Aptitude

Question
What is the rate of interest p.c.p.a.? I. An amount doubles itself in 5 years on simple interest. II. Difference between the compound interest and the simple interest earned on a certain amount in 2 years is Rs. 400. III. Simple interest earned per annum is Rs. 2000
Options
A. I only
B. II and III only
C. All I, II and III
D. I only or II and III only

Correct Answer

I only or II and III only

Explanation

$I . \frac{P * R * 5}{100} = P ? R = 20$

$I I . P {(1 + \frac{R}{100})}^{2} - P - \frac{P * R * 2}{100} = 400 = > p R^{2} = 4000000$

$I I I . \frac{P * R * 1}{100} = 2000 = > P R = 200000$

$\frac{P R^{2}}{P R} = \frac{4000000}{200000} ? R = 20$

Thus I only or (II and III) give answer.

Correct answer is (D)