Question

In what time will a sum of money doubles itself at 5%interest per annum​

Answer 1

Answer:

per 20 years the sum of money will be doubles itself

Step-by-step explanation:

Given a sum of money doubled itself at 5% interest per year

   let the principal amount  'a' and it is doubled  at time  't'  at rate 5%  

   the total sum of money after time 't' =  2a

    formula for total amount = $p [ 1 +\frac{TR }{ 100} ]$  [ T= time, R= rate ]

                                       2a =  $a [ 1 + \frac{ (t)(5)}{ 100} ]$

                                        2a =   $a[ \frac{ 100+ 5t }{ 100} ]$

                                         2 = $\frac{100+5t }{100 }$

                                        200 =  100+5t

                                       200-100= 5t

                                       5t = 100

                                         t = 20 years