To find the rate of compound interest per annum at which a sum of Rs. 1200 becomes Rs. 1348.32 in 2 years, we use the compound interest formula for the amount:

A=P(1+R100)nA=P\left(1+\frac{R}{100}\right)^nA=P(1+100R​)n

Where:

• A=1348.32A=1348.32A=1348.32 (final amount)
• P=1200P=1200P=1200 (principal)
• n=2n=2n=2 years
• RRR = rate of interest per annum (unknown)

Substituting the values:

1348.32=1200(1+R100)21348.32=1200\left(1+\frac{R}{100}\right)^21348.32=1200(1+100R​)2

Divide both sides by 1200:

1348.321200=(1+R100)2\frac{1348.32}{1200}=\left(1+\frac{R}{100}\right)^212001348.32​=(1+100R​)2

1.1236=(1+R100)21.1236=\left(1+\frac{R}{100}\right)^21.1236=(1+100R​)2

Taking the square root of both sides:

1.1236=1+R100\sqrt{1.1236}=1+\frac{R}{100}1.1236​=1+100R​

1.06=1+R1001.06=1+\frac{R}{100}1.06=1+100R​

Solving for RRR:

R100=1.06−1=0.06\frac{R}{100}=1.06-1=0.06100R​=1.06−1=0.06

R=6%R=6%R=6%

Therefore, the rate of compound interest per annum is 6%. This matches the detailed solutions found in multiple sources