A sum of money at some rate of simple interest amounts to 2900 Rs. in 8 years and to 3000 Rs. In 10 years. The rate of interest per annum is :
A sum of money at some rate of simple interest amounts to 2900 Rs. in 8 years and to 3000 Rs. in 10 years. The rate of interest per annum is :
[A]2%
[B]2.5%
[C]3%
[D]4%
2%
Principal + interest for 8 years = 2900 Rs…………(I)
Principal + interest for 10 years = 3000 Rs……..…(II)
Subtracting equation (I) from (II)
Interest for 2 years = 100 Rs.
∴ Interest for 8 years = 400 Rs.
From equation (I),
Principal = (2900 – 400) = 2500 Rs.
$latex \therefore Rate = \frac{SI\times 100}{Princ.\times Time}&s=1$
$latex = \frac{400\times 100}{8\times 2500} = 2\%&s=1$
Hence option [A] is correct answer.