Albert invested an amount of x rupees in a fixed deposit scheme offering 10% per annum for 1st year and 15% per annum for 2nd year and rece…

I think 16000 is right

Solution:

Formula: S.I = (P × n × r)/100 where,

P = Principal amount

n = time in years and

r = rate of interest in percentage

Given: Principal amount is 'x'

S.I for the first year, S.I 1 = ( x × 1 × 10)/100

S.I 1 = x/10 --------> 1

S.I interest for the second year, S.I 2 = ( x + S.I 1)× 1 × 15/100

S.I 2 = 3(x + S.I 1)/20 ----------> 2

Substituting eqn 1 in 2 we get

S.I 2 = 3[x +(x/10)]/20

S.I 2 = 3[(10x +x)/10]/20

S.I 2 = 3[11x]/200

S.I 2 =33x /200 ---------> 3

It is given that final amount for the 2 years = Rs. 20,240

So, x + S.I 1 + S.I 2 = 20240

Substituting eqn 1 and 3 we get

x + (x/10) + (33x/200) = 20240

( 200x + 20x + 33x )/200 = 20240

253x/200 = 20240

x = (20240 × 200)/253

x = 16,000

So, the principally invested money is Rs.16,000/-.

The correct option is 2). 16,000