Question

if a sum triples in 15 years at simple rate of interest the rate of interest per annum will be? ​

Answer 1

Answer:

Let Principal be Rs x

Then amount = Rs 3x

Then interest = Rs 2x

Time = 15 years

Let rate per annum be r%

A. T. P, 2x = (x*15*r)/100

or, r = 200/15 = 13.33%

Answer 13.33%

Hope it helps

Answer 2

$\sf\underline{Step-by-step \: explanation}$

Let the principal be x.

Given,

P = x (Assumption)

A = 3x (Acc. to the assumption)

R = R

T = 15 years

S.I. = 2x (A - P = 3x - x = 2x)

Applying the method to find the rate,

Which is,

$\sf\dfrac{si \: \times \: 100}{p \: \times \: t}$

Solving,

R =

$\sf\dfrac{2x \: \times \: 100}{x \: \times \: 15}$

R =

$\sf\dfrac{200x}{15x}$

After Cancellation...

13.33 %

Which can either be rounded off and can be left as it is.

So, the rate will be,

13.33 % (Without rounding off)

13 % (Rounding off)