In how many years will a certain amount double, if it attracts 5%
interest rate compounded annually?

In about 14.21 years a certain amount will double if it attracts 5%  interest rate compounded annually

Step-by-step explanation:

The formula for compound interest, including principal sum, is

 , where

∵ A certain amount is double in t years

- That means A is double P

∴ A = 2 P

∵ It attracts 5%  interest rate compounded annually

∴ r = 5% = = 0.05

∴ n = 1 ⇒ compounded annually

- Substitute all of these values in the formula above

∵

∴  

- Divide both sides by P

∴  

- Insert ㏑ for both sides

∴

- Remember = t . ㏑(1.05)

∴ ln(2) = t . ㏑(1.05)

- Divide both sides by ㏑(1.05)

∴ 14.2067 = t

- Round it to the nearest hundredth

∴ t = 14.21 years

In about 14.21 years a certain amount will double if it attracts 5%  interest rate compounded annually

so then what are you asking?

step-by-step explanation:

answer:   c ?

step-by-step explanation: