Question

A lent rs. 1200 to b for 3 years at a certain rate of simple interest and rs. 1000 to c for the same time at the same rate. if he gets rs. 50 interest more from b than from c, then the rate percent is

Answer 1

The rate of percent is 500

Answer 2

Given :

A lent B Rs. 1200 and C Rs. 1000

SI received from C is Rs. 50 more than B

To Find :

Rate percent

Solution :

Let 'R' be the rate percent per annum.

Case 1 : A lent money to B

Principal (P) = Rs. 1200

Time (T) = 3 years

We know,

    Simple Interest (SI₁) = $\frac{P*R*T}{100}$

                                     =  $\frac{1200 * 3 * R }{100}$

                                     = 36R

Case 2 : A lent money to C

Principal (P) = Rs. 1000

Time (T) = 3 years

Simple Interest (SI₂) = $\frac{P*R*T}{100}$

                                 =  $\frac{1000 * R * 3}{100}$

                                 = 30R

As per question,

           SI₁  -  SI₂      =  50

⇒        36R - 30R    =  50

⇒          6R              =  50

⇒            R              =  $\frac{50}{6}$

∴             R              =  8.33%

Therefore, the rate percent per annum is 8.33%.