A sum of money amounts to 850 Rs. in 3 years and to 925 Rs. in 4 years at some rate of simple interest. The sum is :
A sum of money amounts to 850 Rs. in 3 years and to 925 Rs. in 4 years at some rate of simple interest. The sum is :
[A]550 Rs.
[B]600 Rs.
[C]625 Rs.
[D]700 Rs.
625 Rs.
Interest for 1 year= (925 – 850) = 75 Rs.
∴ If a sum becomes $latex a_{1}$ in $latex t_{1}$ years and $latex a_{2}$ in $latex t_{2}$ years then rate of interest
$latex = \frac{100(a_{2}-a_{1})}{a_{1}t_{2} – a_{1}t_{1}}\%&s=1$
$latex = \frac{100(925-850)}{850\times 4- 3\times 925} = \frac{7500}{625} = 12\%&s=1$
$latex \therefore Principal = \frac{SI\times 100}{Time\times Rate}&s=1$
$latex = \frac{75\times 100}{1\times 12} = 625\ Rs.&s=1$
Hence option [C] is correct answer.