Help me with this Econs question, please...thank you!

Grace period is a period of time before the credit card company starts charging late fees. truefalse

Amathematical approximation called the rule of 70 tells us that the number of years that it will take something that is growing to double in size is approximately equal to the number 70 divided by its percentage rate of growth. thus, if mexico's real gdp per person is growing at 7 percent per year, it will take about 10 years(=70/7) to double. apply the rule of 70 to solve the following problem. real gdp per person in mexico in 2005 was about $11,000 per person, while it was about $44,000 per person in the u. s. if real gdp per person in mexico grows at the rate of 5 percent per year: how long will it take mexico's real gdp per person to reach the level that the united states was at in 2005? (hint: how many times would mexico's 2005 real gdp per person have to double to reach the u. s.'s 2005 real gdp per person?

Franklin painting company is considering whether to purchase a new spray paint machine that costs $4,800. the machine is expected to save labor, increasing net income by $720 per year. the effective life of the machine is 15 years according to the manufacturer’s estimate. required determine the unadjusted rate of return based on the average cost of the investment.