Kathy deposits $25 into an investment account with an

A sample of bacteria is decaying according to a half-life model. If the sample begins with 200 bacteria and after 5 minutes ther

77julia77 [94]

<h2>Hello!</h2>

The answer is:

There will remain a total of 134 bacteria after 7 minutes.

Exponential decay calculations are commonly used to find the decrease of amounts of populations, bacterias, and other situations when using proportional relationships. In order to find the problem, we must remember the equation used to calculate the exponential decay.

$Decay=S(1-r)^{t}$

Where,

S, is the starting value/amount

r, is the rate (% to real number)

t, is the time elapsed.

We are given that the numbers of bacteria decrease by 50 after 5 minutes, starting with 200, and after 5 minutes the number of bacteria is 150

Calculating the rate of decrease, we have:

$Rate=\frac{Decrease}{Starting}=\frac{200-150}{200}=\frac{50}{200}=0.25$

Therefore, the rate of decrease is 0.25 or 25% (after multiplying the number by 100)

Then, substituting the given information and the rate of decrease into the decay equation, we have:

$Decay=200(1-0.25)^{\frac{t}{5}}$

Now, to calculate how many bacteria will remain after 7 minutes, we need to substitute it into the decay equation:

$Bacteria(After7Minutes)=200(1-0.25)^{\frac{7}{5}}=133.69$

So, rounding to the nearest whole number, there will remain a total of 134 bacteria after 7 minutes.

Have a nice day!

3 0

2 years ago

What is the slope of the line shown below?

Valentin [98]

1/6

Step-by-step explanation:

7 0

2 years ago

Read 2 more answers

Two faces of a six-sided die are painted red, two are painted blue, and two are painted yellow. The die is rolled three times, a

Keith_Richards [23]

Answer:

(a) 4/9

(b) 19/27

Step-by-step explanation:

The probability of each die turning up red or not turning red are:

$P(R) =\frac{2}{6}= \frac{1}{3}\\P(O) =\frac{4}{6}= \frac{2}{3}$

(a). Exactly one face up is red.

The odds of only the first die being red are:

$P(A=R) =\frac{1}{3} *\frac{2}{3}* \frac{2}{3} \\P(1=R) =\frac{4}{27}$

The same odds are valid for only the second or only the third die being red. Therefore, the probability that exactly one die turns up red is:

$P(R=1) = 3*\frac{4}{27}\\P(R=1) = \frac{4}{9}$

(b). At least one face up is red.

The probability that at least one die turns up red is the sum of the probabilities of exactly one (found in the previous item), two or all dice turning up red.

Following the same logic as in the previous item, the probability that exactly two dice turn up red is:

$P(R=2) = 3*(\frac{1}{3}*\frac{1}{3}*\frac{2}{3})\\P(R=2) = \frac{2}{9}$