Aptitude ➤ Compound Interest ➤ Set 1

#### Compound Interest : Important Facts and Formulae

Let Principal = P, Rate = R % per annum (p.a.) and Time = n years. Then,

I. When interest is compound Annually:
Amount = P(1+R/100)n

II. When interest is compounded Half-yearly:
Amount = P[1+(R/2)/100]2n

III. When interest is compounded Quarterly:
Amount = P[ 1+(R/4)/100]4n
Question 1
Q1.  The compound interest on Rs. 30,000 at 7 % per annum is Rs. 4347. The period (in years) is:
Question 2
Q2.  What will be the compound interest on a sum of Rs. 25,000 after 3 years at the rate of 12 p.c.p.a.?
Question 3
Q3.  At what rate of compound interest per annum will a sum of Rs. 1200 become Rs. 1348.32 in 2 years?
Question 4
Q4.  The difference between compound interest and simple interest on an amount of Rs. 15,000 for 2 years is Rs. 96. What is the rate of interest per annum ?
Question 5
Q5.  The compound interest on a certain sum for 2 years at 10 % per annum is Rs. 525. The simple interest on the same sum for double the time at half the rate percent per annum is: