Exponential Function Word Problem

Solve this problem: When the apocalypse began, there were 5 zombies. Each day that number tripled. How many zombies would there be after a week (7 days)?

Mathematical Equivalence

ON

Write an equation for this problem: A population of 1200 bacteria is doubling each day for x days.

What would be the multiplier for this problem?

Matt has the chicken pox. On day one, he counted that he had 10 spots. Each day that number quadruples. How many would he have after 3 days?

• 10

• 3

• 4

• 1/4

• 1/3

Write an equation that models the following situation:

Samantha's hair was known to grow very rapidly. It began at a length of 6 in and grew at a rate of 14% a week.

• y=6(0.14)^x

• y=6(1.14)^x

• y=6(1+14)^x

• y=6(0.86)^x

Which of the following functions shows an initial amount of $15 and an increase of 35% each year?

• y = 15(35)^x

• y = 15(0.35)^x

• y = 15(1.35)^x

• y = 35(1.15)^x

The value of a car is $15,000 and depreciates at a rate of 8% per year. What is the exponential equation?

• y=8(15,000)^x

• y=15,000(0.92)^x

• y=15,000(1.08)^x

• y=15,000(0.08)^x

Suppose a culture of bacteria begins with 5000 cells and dies by 30% each year. Write an equation that represents this situation.

• y=5000(0.7)^x

• y=5000(1.3)^x

• y=30(5000)^x

• y=5000x^x

A population of 1200 bacteria is doubling each day for x days.

A population of 1500 deer decreases by 1.5% per year. Which function can be used to determine the number of deer, y, in this population at the end of t years?

• y = 1500(1 - 0.015)^t

• y = 1500(0.015)^t

• y = 1500(1 + 0.015)^t

• y = 1500(1.5)^t

Suppose a culture of bacteria begins with 5000 cells and dies by 30% each year. The equation that represents this situation is y = 5000(0.7)^t where t = time. How many bacteria cells will be present after 2 years?

• 24500

• 20450

• 2450

• 245