1. If a pond lily doubles everyday and it takes 30 days to completely cover a pond, on what day will the pond be 1/4 covered?

    1. day 4
    2. day 8
    3. day 15
    4. day 20
    5. day 28



  2. If a pond lily doubles everyday and it takes 30 days to completely cover a pond, on what day will the pond be 1/2 covered?

    1. day 15
    2. day 20
    3. day 25
    4. day 28
    5. day 29



  3. The amount of lillies produced between day 29 and day 30 is

    1. equal to the entire amount of lillies produced previously
    2. is twice as large as that produced between day 14 and day 15
    3. about the same as produced between day 28 and day 29
    4. the same as between any 2 days since the growth rate is constant






  4. What is the doubling time of the entire lily pond?

    1. 1 day
    2. 2 days
    3. 10 days
    4. 20 days
    5. 30 days




  5. A different lilly pond has more nutrients and has a pond doubling time of 16 days. On approximately what day is 10% of the pond covered?



    1. day 1
    2. day 2
    3. day 5
    4. day 9
    5. day 13



  6. The current population of Eugene is 140,000 people. If the population growth rate remains at 4% per year, approximately when will the city of Eugene have 500,000 people?

    1. the year 2010
    2. the year 2022
    3. the year 2035
    4. the year 2050
    5. the year 2095



  7. Resource X is currently being used at the rate of 100 units per year. The current growth rate is 10%. This growth rate is expected to remain this way for the next 14 years. In year 15 and beyond, the growth rate will reduce from 10% to 5%. In 28 years, what will be the usage rate of resource X?

    1. 200 units per year
    2. 400 units per year
    3. 800 units per year
    4. 1600 units per year
    5. 3200 units per year