Question

Bacteria in a petri dish is experiencing exponential decay. There are 1,000 bacteria at the start and 400 bacteria a day later.

The percent decrease is percent, and the decay factor is .
a) 100, 0.4
b) 60, 0.4
c) 40, 0.6
d) 100, 0.6

Answer 1

The percent decrease is 60% and the decay factor is 0.4.

Step-by-step explanation:

The exponential decay of bacteria in a petri dish can be determined by calculating the percent decrease and the decay factor. In this case, we start with 1,000 bacteria and after a day, there are 400 bacteria remaining. To calculate the percent decrease, we can use the formula:

Percent Decrease = (Initial Value - Final Value) / Initial Value * 100

Plugging in the values, we get:

Percent Decrease = (1000 - 400) / 1000 * 100 = 60%

The decay factor can be calculated by dividing the Final Value by the Initial Value:

Decay Factor = Final Value / Initial Value = 400 / 1000 = 0.4

Therefore, the correct answer is option b) 60, 0.4.