Answer Interest rate = 12.3%
The compound interest formula is given by:
Where
A = Future amount
P = Present amount (Principal amount)
r = Interest rate in decimal form
n = No. of times compounded per year
t = time in years.
We can say that if:
Present amount = P
Future amount = 3P
r = 12.3/100 = 0.123
n = 1
t = ?
Substitute the values in the formula of compound interest:
Taking log on both sides.
Round off to nearest option
t ≅ 9 years
