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
Vinil7 [7]
3 years ago
5

An absentminded professor does not remember which of his 12 keys will open his ocedoor. Suppose he tries them at random and with

replacement. Find the probability that heopens his oce door after three tries.
Mathematics
1 answer:
kipiarov [429]3 years ago
8 0

Answer: 0.0052

Step-by-step explanation:

Total number of times experiment was performed (n)= 12

Probability of the event (that one key out of a total of 12 opens the door) = 1/12 = 0.083

Hence, p = 0.83

q = 1 - p = 11/12 = 0.917

x = 3

Since the experiment was performed n number of times, a binomial probability distribution can defined the experiment.

P(x=r) = nCr ×p^r × q^n-r

P(x=3) = 12C3 × (0.083)⁴ × (0.917)^8

P(x=3) = 220 × (0.083)⁴ × (0.917)^8

P(x=3) = 0.0052

You might be interested in
There are 24 different tables to set up for field day.The principal wants the tables set up in equal rows.should she use 3 rows
Ira Lisetskai [31]
There should be 3 rows because 24 divided by 3 equals 8.
8 0
2 years ago
665.8 rounded to the nearest tenth of a cubic meter
sukhopar [10]

If the digit after tenth is greater than or equal to 5, add 1 to tenth. Else remove the digit. Example

124.58

The first number of right of decimal point is 5

The second digit after decimal point is 8 which is greater than 5

So add 1 to 5

Result = 124.6

no answer just explanation,

5 0
2 years ago
The length of a swimming pool is 8m longer than its width and the area is 1o5m2?
Nina [5.8K]
Let the breadth be x
length=x+8
according to the question
area of the pool = l*b
105=x*x+8
if u solve this equation further u will get the answer
5 0
3 years ago
Read 2 more answers
If Florist B increases the cost per rose to $5.20,for what number of roses is it less expensive to order from Florist A? From Fl
Alenkinab [10]

Answer:

For<em> </em>38 roses at <em>$5.15</em> per rose, Florist A is Less Expensive then Florist B

For<em> </em>34 roses at <em>$5.20</em> per rose, Florist A is Less Expensive then Florist B

Step-by-step explanation:

The Full Question Reads:

<u><em>Derek wants to order some roses online.  Florist A charges $4.75 per blue rose plus $40 delivery charge.  Florist B charges $5.15 per red rose plus $25 delivery charge.  If Florist B increases the cost per rose to $5.20, for what number of roses is it less expensive to order from Florist A?  From Florist B?</em></u>

To begin we need to understand our given information and what we are actually looking for.

<u>Given Information</u>

Florist A:

charges $4.75 per blue rose

charges $40 per delivery

Florist B:

charges $5.15 per red rose

charges $25 per delivery

Note: in this problem we ignore the colour of the rose (red or blue) as it does not affect our solution or contributes to it. Therefore we shall call our first variable representing the number of roses as x.

The next step is to construct a system of equations representing our problem and our given information. Here we are looking at linear relationships so a linear function of the form:

y=ax+b   Eqn(1).

<em>will suffice where</em>

y: represents the total cost from the Florists (i.e. number of roses and delivery charges). Dependent Variable

x: represents the number of roses purchased from the Florists. Independent Variable

a: is our relationship factor between y and x

b: is our constant which in this problem is the <em>delivery charge</em> value for each florist.  

Since we have two Florists, we will construct two equations, one for each florist, by employing Eqn(1).  and our given information as follow:

Florist A:  y=4.75x+40   Eqn(2).

Florist B:  y=5.15x+25   Eqn(3).

By employing both equations above and writing them as an inequality <em>since we are looking for which value of </em>x<em> (i.e. number of roses) will the less expensive Florist be and then solving for </em>x<em> we have: </em>

<em>4.75x+40</em>

<em>4.75x-5.15x       Gathering all similar terms together</em>

<em>-0.4x                       Simplifying</em>

<em>x>\frac{-15}{-0.4}\\                             Solving for x </em>

<em>x>37.5</em>

<em>(note how < changes to > since any multiplication/devision process of negative sign in an Inequality will change the order of < to > and vice versa). </em>

Since a rose has to be sold as a whole and not half we will say that <em>x>38</em> So we can then plug in the value of x in Eqn(2) and Eqn(3) and find the cost of buying more than 38 roses from each:

Eqn(2):  Florist A:  y(x>38)=4.75*38+40=220.5  

Eqn(3):  Florist B:  y(x>38)=5.15*38+25=220.7

Which tells us that Florist A is less expensive than Florist B by $0.20 for a purchase of more than 38 roses.

Next the question tells us that Florist B increases the cost from $5.15 to $5.20 per rose, which in Eqn(3) denotes our a value and thus Eqn(3). now becomes:

Florist B:  y=5.20x+25   Eqn(3).

Applying the same method like before and solving for the value of x<em> we have: </em>

<em>4.75x+40</em>

<em>4.75x-5.20x       Gathering all similar terms together</em>

<em>-0.45x                       Simplifying</em>

<em>x>\frac{-15}{-0.45}\\                           Solving for x </em>

<em>x>33.3</em>

Similarly as a rose has to be sold as a whole and not half we will say that <em>x>34</em> So we can then plug in the value of x in Eqn(2) and Eqn(3) and find the cost of buying more than 34 roses from each:

Eqn(2):  Florist A:  y(x>34)=4.75*34+40=201.5  

Eqn(3):  Florist B:  y(x>34)=5.15*34+25=201.8

Which tells us that Florist A is again less expensive than Florist B by $0.30 for a purchase of more than 34 roses. It was also shown that as the cost of the rose increased by $0.05 the number of roses for purchase decreased.

4 0
3 years ago
Express 1/3 as a repeating decimal and round to the nearest hundredth.
katrin [286]

Answer:

1/3 is .333... so you can write .33.... or .33 with a line on top of the 3's

Step-by-step explanation:

.3 is in the tenths and .33 is in the hundredths place

3 0
2 years ago
Other questions:
  • Find a recursive rule for the sequence 2 4 6 10
    6·1 answer
  • Color and draw to show a way to take apart 7. complete the subtraction sentence
    8·1 answer
  • Luke borrowed $15,000 to pay his
    6·1 answer
  • Which of the following transformations affect the y-values of a function? (Check all that apply)
    13·2 answers
  • Find the area of the triangle below. Be sure to include the correct unit in your answer.
    5·2 answers
  • Graph ƒ(x) = -3x + 7
    6·1 answer
  • Whick property is used to solve the following problem: 8( 7 - 3)
    13·2 answers
  • So there teams and you had to put the highest value and the lowest ones the numbers are 20 -25 -10 25 -15 how would you put them
    12·2 answers
  • Which equation is represented by the graph below
    5·1 answer
  • Which of the following expressions is equivalent to.
    15·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!