The number of bacteria in a flask grows according to the differential equation dy = 0.08y dt In this question, time is measured in hours and the number of bacteria, y, is measured in millions. The number of bacteria at time t = 0 is 3 million a. Enter a formula for the number of bacteria at time y = b. What is the value of the growth constant? Growth constant : per hour. c. How long does it take for the number of bacteria to double? (Enter your answer correct to two decimal places.) Doubling time : hours. d. How many million bacteria will be present after 7 hours have passed? (Enter your answer correct to one decimal place.) Number present after 7 hours : million. "symbolic formatting help 3. [-/3 Points] DETAILS MY NOTES An isotope of a radioactive element has decay constant equal to 0.06 per year. Initially, there are 6 million atoms of the isotope present. Since the isotope decays exponentially, the number of atoms obeys the following equation P = 6e-0.06t In this question, time is measured in years and the number of atoms, P, is measured in millions. a. What is the value of the decay constant? Decay constant : per year. b. What is the half-life of the isotope? (Enter your answer correct to two decimal places.) Half-life : years c. How many million atoms will be present after 4 years have passed? (Enter your answer correct to one decimal place.) Number present after 4 years : million. 4. [-/3 Points] DETAILS MY NOTES An isotope of a radioactive element has half-life equal to 4 thousand years. How old is the sample? Imagine a sample that is so old that most of its radioactive atoms have decayed, leaving just 4 percent of the initial quantity of the isotope remaining. Give your answer in thousands of years, correct to one decimal place. Age : thousand years