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Paul [167]
3 years ago
9

A sample of bacteria is decaying according to a half-life model. If the sample begins with 800 bacteria, and after 13 minutes th

ere are 320 bacteria, after how many minutes will there be 15 bacteria remaining? Round your answer to the nearest whole number.
Mathematics
1 answer:
nikklg [1K]3 years ago
3 0

Answer:

56.42 minutes

Step-by-step explanation:

The initial sample= y0 = 800

After 13 minutes , amount = 320

Y= y0e-kt

320 = 800e-k(13)

320/800 = e-k13

0.4 = e-k13

In0.4 = -k13

-0.91629= -k13

0.07048= k

Y = 800e-0.07048t

Minutes when the bacterial present will be 15

15 = 800e-0.07048t

15/800= e-0.07048t

0.01875 = e-0.07048t

In 0.01875 = -0.07048t

-3.97656 = -0.07048t

-3.97656/-0.07048= t

56.42 = t

56.42 minutes

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The slope of a line is 2/6 because slope also means rise over run (y/x). So the line's slope is 2/6 because it goes up (rises) in the y-direction 2 units and moves to the right (runs) 6 units, from one point to another.

Step-by-step explanation:

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<span> (3 + 1/4 u^4 − 2/3 u^9) du</span>

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You have 800 quarter-inch-long beads. If you use them all to make 16 bracelets, what will be the rate of beads per bracelet?
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HELPPPPPPPPP<br><br> Write the quadratic expression to represent the pattern to the right
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Answer:

  • n^2 + 2n - 1

Step-by-step explanation:

<u>Figure 1</u>

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<u>Figure 2</u>

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<u>Figure 3</u>

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3 years ago
50,000 contestants participate in an on-line game. The game randomly eliminates 20% of the contestants each day. Determine the n
irga5000 [103]

Answer:10,486 contestants

Step-by-step explanation:

First day:

Total number of contestants at the beginning = 50,000

After first day, 20% 0f 50,000 are removed.

That is, (20/100)×50,000 = 10,000

Contestants remaining after first day = 50,000-10,000 = 40,000

Second day:

Contestants= 40,000

20% removed

That is (20/100)×40000=8000

Balance =40000-8000=32,000

Third day:

Contestants= 32000

20% removed

That is (20/100)×32000=6400

Balance =32000-6400=25,600

Fouth day:

Contestants= 25,600

20% removed

That is (20/100)×25,600=5,120

Balance =25,600-5,120=20,480

Fifth day:

Contestants= 20,480

20% removed

That is (20/100)×20,480=4096

Balance =20,480-4096=16,384

Sixth day:

Contestants= 16,384

20% removed

That is (20/100)×16,384=3276.8

Balance =16,384-3276.8=13,107.2

Seventh day:

Contestants= 13,107.2

20% removed

That is (20/100)×13,107.2=2621.44

Balance =13107.2-2621.44=10485.76

Therefore, number of contestants remaining after one week equals 10,486.

6 0
3 years ago
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