need help with the following with explanation

Page 62: problems 1, 2,9, 10,14, 20, 24,42, 44 and 48 I For Problems 12, nd k such that p = pOeAkt has the given doubling time. 1.10 2.0.4 9. If a bank pays 1.25% per year interest compounded continuously, how long does it take for the balance in an account to double? 10. Find the doubling time of a quantity that is increasing by 7% per yean 14. Oil consumption in China grew exponentially96 from 8.938 million barrels per day in 2010 to 10.480 million barrels per day in 2013. Assuming exponential growth continues at the same rate, what will oil consumption be in 2025? 20. A population, currently 200, is growing at 5% per year. (a) Write a formula for the population, P, as a function of time, t, years in the future. (b) Graph P against t. (c) Estimate the population 10 years from now. (d) Use the graph to estimate the doubling time of the population. 24. The half-life of a radioactive substance is 12 days. There are 10.32 grams initially. (a) Write an equation for the amount, A, of the substance as a function of time. (h) when is the substance reduced to 1 gram? 42. Find the future value in 15 years of a $20,000 payment today, if the interest rate is 3.8% per year compounded continuously. 44. Find the present value of a $20,000 payment to be made in 10 years. Assume an interest rate of 3.2% per year compounded continuously. 48. A business associate who owes you $3000 offers to pay you $2800 now, or else pay you three yearly installments of $1000 each, with the rst installment paid now. If you use only nancial reasons to make your decision, which option should you choose? Justify your answer, assuming a 3% interest rate per year, compounded continuously