1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
Karo-lina-s [1.5K]
3 years ago
7

In a parenting magazine, Mrs. Smith read an advertisement about all the different ways that bleach can be used to kill bacteria.

The advertisement claimed that some forms of bacteria triple in amount after each hour. Consider the situation where one bacterium is found on Mrs. Smith's countertop at home.
Mathematics
1 answer:
babymother [125]3 years ago
8 0

Question:

(a) How many bacteria would be found in 24 hours

(b) How many bacteria would be found in 2 days

(c) How long for 1000 bacteria to be found

Answer:

(a) 282429536481 bacteria

(b) 7.97*10^{22 bacteria

(c) 6 days

Step-by-step explanation:

The question illustrates an exponential function

y = ab^x

Where

a = Initial\ Value = 1

b=Rate = 3 --- i.e. triples

x = number\ of\ hours

Solving (a): Bacteria in 24 hours

In this case:

x = 24

Substitute x = 24, b = 3 and a = 1

So:

y = ab^x

y = 1 * 3^{24

y = 1 * 282429536481

y = 282429536481 bacteria

Solving (b): Bacteria in 2 days

2\ days =48\ hours

So:

x = 48

Substitute x = 48, b = 3 and a = 1

So:

y = ab^x

y = 1 * 3^{48

y =7.97*10^{22 bacteria

Solving (c): How long for 1000 bacteria

In this case:

y = 1000

Substitute y = 1000, b = 3 and a = 1

So:

y = ab^x

1000 = 1 *3^x

1000 = 3^x

Take Log of both sides

Log1000 = Log3^x

This gives:

Log1000 = xLog3

Make x the subject

x = \frac{Log1000}{Log3}

x \approx 6

<em>Hence: It takes 6 days</em>

You might be interested in
james' daily wage was $5 more than Davis's. Although James worked 3 days less than David, they earned $180 each. Find the number
zalisa [80]

Answer: 9 days

Step-by-step explanation:

Let x represent James' daily wage

James' daily wage was $5 more than Davis's. It means that Davis's daily wage will be $(x-5)

Let y represent number of days that James worked. James worked 3 days less than David. It means that the number of days that Davis worked would be (y + 3) days

they earned $180 each. Total amount of money earned by either of of them is the product of wage and the number of days worked.

Since James earned $180, then

180 = xy - - - - - - - - 1

Since Davis also earned $180, then

180 = (x - 5)(y + 3)

xy +3x -5y -15 = 180 - - - - - - - - 2

Substituting xy = 180 into equation 2

It becomes

180 + 3x - 5y -15 = 180

3x - 5y = 180 - 180 + 15

3x - 5y = 15 - - - - - - -3

From equation 1, x = 180/y

Substituting x = 180/y into equation 3, it becomes

3 × 180/y - 5y = 15

540 - 5y^2 = 15y

5y^2 + 15y -540 = 0

Dividing through by 5

y^2 + 3y -108 = 0

y^2 + 12y - 9y -108 = 0

y(y + 12) - 9(y + 12) = 0

y + 12 = 0 or y - 9 = 0

y = -12 or y = 9

Since the number of days cannot be negative, then,

Number of days that James worked will be 9 days

8 0
3 years ago
IS THIS IN SIMPLIST FORM? PLEASE HELP! TY! <br><br> 2( x - 3 + 2 )
Phoenix [80]

Answer:

2x - 2

Step-by-step explanation:

There are two steps to take here.  First add together the -3 + 2 in the brackets:

2(x - 3 + 2)

= 2(x - 1)

Now use the distributive property and multiply each term in the brackets by two:

2(x - 1)

= 2x - 2

And you now have it in simplest form.

3 0
2 years ago
Can someone plz help me with this one problem plzzzzz!!!<br><br> (I’M MARKING BRAINLIEST)!
liraira [26]

Answer:

1:5

5:9

7:11

9:13

I think this is right in not sure though

8 0
3 years ago
Read 2 more answers
Which of these is the algebraic expression for "3 less than the product of 4 and some number?"
svet-max [94.6K]

Answer:

4s - 3

hope this helps!

Step-by-step explanation:

7 0
3 years ago
Andy was given data to draw 3 scatter diagrams.
vredina [299]

Answer:

A) Negative Correlation. B) C. C) B

Step-by-step explanation:

<h2>A:</h2>

As the line of best fit is travelling downwards, it is a negative correlation, if the line of best fit is travelling upwards, it is a positive correlation, if the points on the graph are all over the place, there is no correlation.

<h2>B:</h2>

As there are only three types of correlation, the strongest is always the positive.

<h2>C:</h2>

The answer is B because there is no correlation and that means that there shouldn't be a line of best fit.

6 0
2 years ago
Other questions:
  • Math help please... i will be marking brainly
    12·1 answer
  • Select the correct product.
    7·1 answer
  • brad grew 4 1/4 inches this year and is now 56 7/8 IN tall write and solve an equation to find Brads height at the start of this
    12·2 answers
  • A group of 30 bikers went on a trip. Some
    10·1 answer
  • Math, ,,,,,,,,,,,,,,,,,,,,
    12·2 answers
  • Simplify.
    14·1 answer
  • What is the exponents laws
    12·1 answer
  • What does situation mean in math?
    13·2 answers
  • Help me pleaseeeeeeeeeeee
    8·1 answer
  • It was 7 °F outside. The temperature dropped 16º.
    10·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!