Question

At the beginning of year 2011, a man had Rs 22,000 in his bank account. He saved some money by the end of this year and deposited it in the bank. The bank pays 10% per annum compound interest and at the end of 2012 he had Rs 39,820 in his bank account. Find what amount of money he had saved and deposited in his account at the end of year 2011.

Answer 1

His Bank balance at the begining of 2011} Rs 22000
Interest (a) $10\%$ for $1^{st}year=Rs220$
Total Amount = Rs 24200
Let the money added at the end of 2011} Rs x.
So principal at the 2012 $\to$ 24200 + x
Interest (a) $10\%$ on this $=2420+\frac{10x}{100}$
Amount = $(24200+x)+(2420+\frac{10x}{100})$
$Rs39820$ (given)
$(x+\frac{10x}{100})=39820-26620=13200x=\frac{\text{/}{13200}^{1200}}{+\text{/}10}=Rs12000$
He added Rs 12000