Question

if money becomes three times more than initial in 8 years then what is the interest rate ?​

Answer 1

Let Intially Money=₹x. (Principal)

Time=8 years

It become 3 times in 8 years

Amount=₹3x

SI=Amount-Principal

=3x-x

=₹2x

We get

Principal Amount=₹x

Time=8 years

SI=₹2x

We know that

$si = \frac{p \times r \times t}{100} \\ \\ 2x = \frac{x \times r \times 8}{100} \\ \\ r = 2x \times \frac{100}{8x} \\ \\ r = \frac{100}{4} \\ \\ r = 25\%$

Rate=25%

Answer 2

Answer:

Rate of interest = 25%

Step-by-step explanation:

Let the initial money be Rs.x

So, Principal = Rs. x

It becomes 3 times more than initial in 8 years.

Then, Amount = Rs.x × 3 = Rs. 3x

Now,

SI = Amount - Principal

=> SI = 3x - x

=> SI = Rs. 2x

Now,

P = Rs.x

T = 8 years

SI = Rs. 2x

By using the formula of Simple Interest.

S.I. = P × R × T / 100

=> 2x = x × r × 8 / 100

=> r = 2x × 100/8x

'x' is cancelled.

=> r = 2 × 100/8

=> r = 200/8

=> r = 100/4

=> r = 25%

.°. Rate of interest = 25%