A population of bacteria can be modeled by P(t) = 22,000/1+1.2e^-kt. Where t is time in hours and k is constant. After 1 hour the bacteria population is 10,532. What is the value of k rounded to 4 decimal places? My son has already submitted his answer on an online exam, but the teacher didn't explain how they got the answer, and I'm not the greatest with math.

White shapes and black shapes are used in a game. some of the shapes are circles. while the rest are squares. the ratio of the number of white shapes to the number of black shapes is 5: 11. the ratio of the number of white cicrles to the number of white squares is 3: 7. the ratio of the number of black circles to the number of black squres is 3: 8. work out what fraction of all the shapes are circles.