Calculate the following values with the aid of the rule of 72.

a. If the annual growth rate is 0.4% it will takeyears for a country's population to double.

b. If it takes per capita real GDP 42 years to double, then the average annual rate of growth in this variable is%.Enter your response rounded to 2 decimal places.

c. If the annual growth rate in the capital stock is 3% a country's capital stock will double

(Click to select)

once

three times

twice

in 24 years.