Question

simple interest on a certain sum is 16/25 of the sum find the rate percent and the time if both are numerically equal

plz plz reply as soon as possible as tomorrow is my maths annual examination

Answer 1

Let sum = x. Then, S.I = `(16x)/25`

Let rate = R % and time = R years.

`:. (x xx R xx R)/(100)`

`= (16x)/25 or R^2 = (1600)/25 R = 40/5 = 8`

:. Rate = 8% and Time = 8 years.

Answer 2

Let the sum/principal be x.

Given that Simple interest on a certain sum is 16/25 of the sum.

SI = 16/25 * x

    = 16x/25.



Now,

Given that Rate and Time are numerically Equal.

Let the rate of interest and Time be R years.

We know that SI = PTR/100

                        16x/25 = x * R * R/100

                        16x/25 = xR^2/100

                        16/25 = R^2/100

                       1600 = 25R^2

                       1600/25 = R^2

                       64 = R^2

                       R = 8.


Therefore the Rate = 8% and Time = 8 years.


Hope this helps!