Question

The time, in years, that it takes an amount of money to double when invested at a simple interest rate can be approximated by dividing 0.72 by the interest rate expressed as a decimal. Approximately how many years would it take an investment of $1000 to be worth $2000 if the money were invested at a simple interest rate of 4%?

Answer 1

11)

The number of years for the investment to double = 0.72/interest

From the information given,

interest = 4% = 4/100 = 0.04

Therefore,

number of years for the investment to double = 0.72/0.04 = 18

Option 5 is correct