At a simple interest rate of 10% per year, determine how long will it take $10,000 to increase to 4 times as much. Compare the time it will take to double if the rate is 20% per year simple interest.

At an interest rate of 10%, it will take_____ years for the amount to increase 4 times as much.It will take______ years for the amount to double at an interest rate of 20%.