How many years would it take to double your money if the annual interest rate is 9.78%?

If it takes 13 years for consumer index to rise 50%, what's the annual inflation rate? (this means what's the annual price increase rate such that the price level increase 50% over 13 years, something cost $1 will cost $1.5 13 years later.) (round to two decimal places for %, e.g., enter 0.1234 for 12.34%)

When you reach your 1-year birthday, your parents put all the cash gifts they received which totaled to $12,000 to an education account for investment growth and they haven't add any new money to that account since then. When you go to college at age of 18, that account has $26,000 for you to use. What's the annual investment growth rate in that account? (Helpful hint: from age 1 to 18, how many years of annual growth is there?) (round to two decimal places for %, e.g., enter 0.1234 for 12.34%)

Your parents bought their house for $98,000 years ago. Now that house is estimated at a market value of $301,000. If the annual house price appreciation has been around 6.29%, how many years ago did your parent buy their house? (round to two decimal place, e.g. 7.12 years)