Question

A sum of money invested at a certain rate
of interest doubles itself in 8 years. In how
much time will it treble itself at the same
interest rate?​

Answer 1

• There are many different ways to solve this problem but I choose this one

• (SI in case first)/(SI in case second) = (Time in case first)/(Time in case second)

• $SI1/SI2 = T1/T2 \\ </li></ul><p></p><ul><li>1/3 = 8/T2 \\ </li></ul><p></p><ul><li>T2 = 24 \: years</li></ul><p>$

  Explanation:-

  • $SI = P*R*T/100$
  • When principal amount P and rate of interest R is same or constant in both cases then simple interest or the ratio of simple interest will be directly proportional to the time or ratio of time
  • $SI1/SI2 = T1/T2$
  • Ratio of Simple interest in both case will be 1:3
  • In first case the simple interest will be one time of principal amount or initial value because the initial value is becoming double of itself
  • But in second case the simple interest will be 3 times of principal amount or initial value because the initial value is becoming 4 times of itself

  $hope \: its \: help \: u$

Answer 2

Answer:

There are many different ways to solve this problem but I choose this one

(SI in case first)/(SI in case second) = (Time in case first)/(Time in case second)

$\begin{gathered}SI1/SI2 = T1/T2 \\ 1/3 = 8/T2 \\ T2 = 24 \: years\end{gathered} \\ </p><p>SI1/SI2=T1/T2 \\ </p><p>1/3=8/T2</p><p>T2=24years$

Explanation:-

$SI = P*R*T/100SI=P∗R∗T/100$

When principal amount P and rate of interest R is same or constant in both cases then simple interest or the ratio of simple interest will be directly proportional to the time or ratio of time

SI1/SI2 = T1/T2SI1/SI2=T1/T2

Ratio of Simple interest in both case will be 1:3

In first case the simple interest will be one time of principal amount or initial value because the initial value is becoming double of itself

But in second case the simple interest will be 3 times of principal amount or initial value because the initial value is becoming 4 times of itself

$hope \: its \: help \: u$