Exponential Decay

Which equation represents exponential decay?

Jamie's Ford F150 truck was purchased for $29,500. Each year it's worth 80% of what it was worth the year before. Choose the equation that gives the truck's value f(x) after any number of years x.

Which ONE of the following equations represents exponential decay?

Which graph shows exponential decay?

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At a certain point in time, a fossil has 3 picograms of carbon-14. Complete the table with the missing mass of carbon-14 and years

a

b

c

2.38

1.5

11,460

A population of humpback whales has 6,500 whales. Their population is declining such that only 94% of the number of whales remain from the year before. Choose the equation that matches this situation:

Someone drops a basketball from a height of 10 feet. Each time it bounces, the bounce height decreases by 1/3. Which statement is correct?

• The decay rate is 1/3

  and the decay factor is 2/3

• The decay rate is 2/3

  and the decay factor is 1/3

The equation that models how much Acetaminophen is in his body is Calculate how much medicine is left after 10 hours

• 400 milligrams

• 344 milligrams

• 89 milligrams

• 11 milligrams

The population of Townville is decreasing at a rate of 6% each year. If the starting population was 7,000 what equation represents the current population after x number of years?

A 12 inch candle starts to shrink as it melts. It decreases in height by 3% each hour that it burns. Calculate the height of the candle after 4 hours.

• 0.88 inches

• 0.00000972 inches

• 10.62 inches

• 7.78 inches