25-32: Doubling Time. Each exercise gives a doubling time for an exponentially growing quantity. Answer the question (s) about the growth of each quantity.

25. The doubling time of a population of fruit flies 12 hours. By what factor does the population increase in 36 hours in 1 week?

The answer to 25 is 8; 16,384.

29.The initial population of a town is 15,000, and it grows with a doubling time of 10 years. What will the population be in 12 years?24 years?

The answer to 29 is ABOUT 34,461 people; about 79,170 people.

33-34: World population. In 2017, estimate a world population was 7.5 billion. Use the given doubling time to predict the world population in 2027, 2067, and 2117.

33.Assume a doubling time of 40 years.

The answer to 33 is 8.9 billion; 17.8 billion; 42.4 billion.

37-40: Approximate Doubling Time Formula. Use the appropriate doubling time formula (rule of 70). Discuss whether the formula is valid for the case described.

This is number 37. The Consumer Price Index is increasing at a rate of 3.2% per year. What is its doubling time? By what factor will prices increase in 3 years?

The answer 37 is 21.9 years; 1.10.

41-48: Half-Life. Each exercise gives a half-life for an exponentially decaying quantity. Answer about the quantity's decay.

This is 41. The half-life of a radioactive substance is 40 years. if you start with some amount of this substance. what fraction of that amount will remain in 80 years? in 120 years?

The answer to 41 is 1/4; 1/8th.

This is number 45. The current population of a threatened animal species is 1 million, but it is declining with a half-life of 24 years. How many animals will be left in 30 years? in 70 years?

The answer to this about 120,000 animals; about 132,000 animals.

49-52: Approximate Half-Life Formula. Use the approximate half-life. Discuss whether the formula is valid for the case described.

This is number 49. Urban encroachment is causing the area of a forest to decline at a rate of 6% per year. What is the appropriate half-life of the forest? Based on this approximate half-life about what fraction of the forest will remain in 50 years?

The answers to 49 are 11.7 years; 0.05.

This is from my Math 140 course at Sacramento City College-online. Understanding Mathematics. A Quantitative Reasoning Approach. 7th Edition. By Bennett Briggs. Course #18374. Please use good grammar, cut long answers to the best of your ability. Watch grammar, spelling, etc. I have included the answers to the problems. Thank you.