Question

A sum of money lent at simple interest amounts to ₹744 in 2 years and to ₹816 in 3 years.find the sum and rate percent.​

Answer 1

Sum of money = Rs. 200

Rate = 136 %

Step-by-step explanation:

Given,Simple Interest for 3 years = Rs.816

         Simple Interest for 1 year = $\frac{816}{3}$

                                                   = Rs.272

        Simple Interest for 2 years = Rs.272 × 2

                                                      =Rs.544

        Amount for 2 years = Rs.744

       We know that,Amount - Interest = Principal

                               744 - 544 = Principal

                               Rs.200 = Principal

Also,Simple Interest for 2 years = $\frac{Principal\times Rate\times Time}{100}$

                     544 = $\frac{200\times Rate\times 2}{100}$

         $Rate = \frac{544\times 100}{200\times 2}$                  

                Rate = 136 %

Answer 2

Answer:

let the principle be P and rate be R

S.I = A - P

ATQ

744-P = PR*2/100 .....(1)

=> 744-P = PR/50

=> PR = 50(744-P)

and also 816-P = 3PR/100...... (2)

so, 816-P = 3*[50(744-P)]/100

=> 81600-100P = 111600-150P

=> 50P = 30000

=> P = 30000/50 = 600

so, R = 50*(744-600)/600 = 12%