Question

A sum of money double itself in 10 years. The number of years it would treble itself is ​

Answer 1

Answer:

In 20 years amount will be tripled. Step-by-step explanation: Given that a sum of money doubles itself in 10 years.

Answer 2

Given :-

A sum of money double itself in 10 years

To Find :-

The number of years it will double itself.

Solution :-

Let the original principal be P

Total time taken to get doubled = 10 y

Amount = Doubled principal

= 2 × P

= 2P

Interest = Amount - Principal

= 2P - P

= P

But Also ,

$Interest\: =\: {\dfrac{P \times R \times T}{100}}$

On inserting the values in the formula

We get ,

$\implies\: P\: =\: {\dfrac{P \times R \times 10}{100}}$

$\implies\: R\: =\: {\dfrac{P \times 100}{P \times 10}}$

$\implies\: R\: =\: 10$

Therefore, rate of interest is 10%

Final Amount = Previous Amount + Int.

=> FA = 2P + P

= 3P

Interest = Amount - Principal

= 3P - P

= 2P

But Also ,

$Interest\: =\: {\dfrac{P \times R \times T}{100}}$

On inserting the values in the formula

We get ,

$\implies\: 2P\: =\: {\dfrac{P \times 10 \times T}{100}}$

$\implies\: T\: =\: {\dfrac{2P \times 100}{P \times 10}}$

$\implies\: T\: =\: 2 \times 10$

=> T = 20

Therefore, it will take 20 years to triple itself.