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1 year ago

How many distinct seven-digit phone numbers can you create from the numbers 4, 4, 5, 6, 7, 7, 7? (e.g. 445-6777 is one example)?

1 answer:

4 0

You have 7 numbers, two numbers 4 , one 5, one 6 and three numbers 7.

From these 7 numbers you can create $7!=1\cdot2\cdot3\cdot4\cdot5\cdot6\cdot7=5040$ phone numbers, but they are not all different.

If you have two numbers 4, then you have to divide obtained number by 2! (the number of all possible permutations of two numbers 4) and since you have three numbers 7 you should divide the obtained number by 3! (the number of all possible permutations of three numbers 7). Then

 $\dfrac{5040}{2!\cdot 3!}= \dfrac{5040}{1\cdot2\cdot1\cdot2\cdot3}=420$ .

Answer: You can create 420 different phone numbers.

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1. Kim works as a book keeper and creates invoices for a variety of companies. Help Kim find the total

Zanzabum

This is about calculation of invoice.

1) Total for the invoice = $2641.25

2) Total for the invoice = $30

3) Total for the invoice = $1925

1) 12 cameras for $200 each

Amount for cameras = 12 × 200 = $2400

25 cables with length of 10 ft each cost $1.25

Amount for 10 ft cables = 25 × 1.25 = $31.25

12 ft specialty cables cost $1.75 per foot

10 of these cables will have length =12 × 10 = 120 ft

Amount for 10 of these cables = 1.75 × 120 = $210

Total for the Invoice = $2400 + $31.25 + $210

Total for the invoice = $2641.25

2) 250 yards of rope costs $500.

Thus, price per yard = 500/250 = $2 per yard

For a customer that wants 15 yard;

Total for the invoice = 15 × $2 = $30

3) Dump truck is rented for $275 per hour. And the minimum is 2 hours per day. This means that anything less than 1 hour, the money paid must be money for 2 hours.

Thus;

On monday; 1 hour will cost; 2 × $275 = $550

On Tuesday; 3 hours will cost; 3 × $275 = $825

On wednesday; 2hours will cost; 2 × $275 = $550

Total for the invoice = 550 + 825 + 550 = $1925

Read more at; brainly.com/question/17745127

8 0

1 year ago

As the number of pages in a photo book increases, the price of the book also increases. There is an additional shipping charge o

wlad13 [49]

Answer:

Step-by-step explanation:

Solve the inequality (20 + 0.5x) + 0.15(20 + 0.5x) ≤ $62.10 for x:

20 + .5x + 3 + 0.75x ≤ 62.10

Combining the x terms, we get:

20 + 3 + 1.25x ≤ 62.10.

Combining the constants on the left:

23 + 1.75x ≤ 62.10

Combining the constants:

1.75x = 39.10

Solving for x: 39.10/1.75 = 22.34

Thus, the max number of whole pages she can have in her book is 22.

4 0

2 years ago

A clinical test on humans of a new drug is normally done in three phases. Phase I is conducted with a relatively small number of

navik [9.2K]

Answer:

A clinical test on humans of a new drug is normally done in three phases. Phase I is conducted with a relatively small number of healthy volunteers. For example, a phase I test of a specific drug involved only 7 subjects.

Step-by-step explanation:

6 0

1 year ago

Marc mows lawns for $25 each lawn, plus $5 for every hour he spends mowing. The equation for his total earnings per lawn is y =

Mila [183]

Answer:

<h2>The flat pay $25 represents the intercept</h2>

Step-by-step explanation:

To answer this question we need to first understand and compare it with the equation of straight line.

i.e $y= mx+c$ which is the equation of line

where m= slope

y= dependent variable

x= independent variable

c= intercept

Given

$y= 25+5h$

comparing both expression we can see that

25 corresponds to c which is the intercept

6 0

1 year ago

Write the quadratic equation whose roots are six and -2 and who’s leading coefficient is 3 use the letter X to represent the var

Artist 52 [7]

Answer:

$3X^{2} - 12X - 36 = 0$

Step-by-step explanation:

6 and - 2 are the only two solutions to the required quadratic equation.

So, if the variable is represented by X then (X - 6) and (X + 2) will be the only two factors of the polynomial function.

Therefore, the equation is

(X - 6)(X + 2) = 0

⇒ $X^{2} - 4X - 12 = 0$

If the leading coefficient of the equation is 3 then we can write the equation as $3X^{2} - 12X - 36 = 0$ (Answer)

6 0

2 years ago