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3 years ago

Solve for the factual of (5!)

Mathematics

1 answer:

Lelu [443]3 years ago

4 0

1×5 or 5×1 would be a factual of it

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7) PG & E have 12 linemen working Tuesdays in Placer County. They work in groups of 8. How many

BabaBlast [244]

Part A

Since order matters, we use the nPr permutation formula

We use n = 12 and r = 8

$_{n}P_{r} = \frac{n!}{(n-r)!}\\\\_{12}P_{8} = \frac{12!}{(12-8)!}\\\\_{12}P_{8} = \frac{12!}{4!}\\\\_{12}P_{8} = \frac{12*11*10*9*8*7*6*5*4*3*2*1}{4*3*2*1}\\\\_{12}P_{8} = \frac{479,001,600}{24}\\\\_{12}P_{8} = 19,958,400\\\\$

There are a little under 20 million different permutations.

<h3>Answer: 19,958,400</h3>

Side note: your teacher may not want you to type in the commas

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Part B

In this case, order doesn't matter. We could use the nCr combination formula like so.

$_{n}C_{r} = \frac{n!}{r!(n-r)!}\\\\_{12}C_{8} = \frac{12!}{8!(12-8)!}\\\\_{12}C_{8} = \frac{12!}{4!}\\\\_{12}C_{8} = \frac{12*11*10*9*8!}{8!*4!}\\\\_{12}C_{8} = \frac{12*11*10*9}{4!} \ \text{ ... pair of 8! terms cancel}\\\\_{12}C_{8} = \frac{12*11*10*9}{4*3*2*1}\\\\_{12}C_{8} = \frac{11880}{24}\\\\_{12}C_{8} = 495\\\\$

We have a much smaller number compared to last time because order isn't important. Consider a group of 3 people {A,B,C} and this group is identical to {C,B,A}. This idea applies to groups of any number.

-----------------

Another way we can compute the answer is to use the result from part A.

Recall that:

nCr = (nPr)/(r!)

If we know the permutation value, we simply divide by r! to get the combination value. In this case, we divide by r! = 8! = 8*7*6*5*4*3*2*1 = 40,320

So,

$_{n}C_{r} = \frac{_{n}P_{r}}{r!}\\\\_{12}C_{8} = \frac{_{12}P_{8}}{8!}\\\\_{12}C_{8} = \frac{19,958,400}{40,320}\\\\_{12}C_{8} = 495\\\\$

Not only is this shortcut fairly handy, but it's also interesting to see how the concepts of combinations and permutations connect to one another.

-----------------

<h3>Answer: 495</h3>

5 0

3 years ago

What is the lateral surface area of a rectangular prism in square inches.

natulia [17]

Answer:

When a prism has its bases facing up and down, the lateral area is the area of the vertical faces.

(For a rectangular prism, any pair of opposite faces can be bases.)

The lateral area of a right prism can be calculated by multiplying the perimeter of the base by the height of the prism.

4 0

3 years ago

If y=12x-2 were changed to y=12x how would the graph of the new function compare with the original

krek1111 [17]

this means that you would go up 12 each time

3 0

3 years ago

Read 2 more answers

1. $239 television; 10% discount 2. $72 game; 20% discount

Fiesta28 [93]

These are 16 questions and 16 answers

Answer:

See below and the attachment.

Explanation:

From 1 to 10, find the sale price to the nearest cent:

1. $239 television; 10% discount

$Sale\text{ }price=Orignal\text{ }price-discount\\ \\ Sale\text{ }price=\$239-10\%\times \$239=\\\\ Sale\text{ }price=\$239-0.10\times \$239=\\\\ Sale\text{ }price=\$239-\$23.9=\$215.10$

2. $72 game; 20% discount

You can also multiply by the factor (1 - % discount);

For instance for 20% discount, the factor is 1 - 20% = 1 -0.20 = 0.80. Which means that you can multiply the original price by the factor 0.80 to get the sale price:

$Sale\text{ }price=Orignal\text{ }price\times factor\\ \\ Sale\text{ }price=\$72\times(1-0.20)=\\\\ Sale\text{ }price=\$72\times0.80=\\\\ Sale\text{ }price=\$57.60$

3. $18.95 football; 15% discount

$Sale\text{ }price=Orignal\text{ }price\times factor\\ \\ Sale\text{ }price=\$18.95\times(1-0.15)=\\\\ Sale\text{ }price=\$18.95\times0.85=\\\\ Sale\text{ }price=\$16.11$

4. $10.99 CD; 25% discount

$Sale\text{ }price=Orignal\text{ }price\times factor\\ \\ Sale\text{ }price=\$10.99\times(1-0.25)=\\\\ Sale\text{ }price=\$10.99\times0.75=\\\\ Sale\text{ }price=\$8.24$

5. $149 MP3 player; 40% discount

$Sale\text{ }price=Orignal\text{ }price\times factor\\ \\ Sale\text{ }price=\$149\times(1-0.40)=\\\\ Sale\text{ }price=\$149\times0.60=\\\\ Sale\text{ }price=\$89.40$

6. $213 ski jacket; 30% discount

$Sale\text{ }price=Orignal\text{ }price\times factor\\ \\ Sale\text{ }price=\$213\times(1-0.30)=\\\\ Sale\text{ }price=\$213\times0.70=\\\\ Sale\text{ }price=\$149.10$

7. $595 refrigerator; 20% discount

$Sale\text{ }price=Orignal\text{ }price\times factor\\ \\ Sale\text{ }price=\$595\times(1-0.20)=\\\\ Sale\text{ }price=\$595\times0.80=\\\\ Sale\text{ }price=\$476.00$

8. $64 video game; 25% discount

$Sale\text{ }price=Orignal\text{ }price\times factor\\ \\ Sale\text{ }price=\$64\times(1-0.25)=\\\\ Sale\text{ }price=\$64\times0.75=\\\\ Sale\text{ }price=\$48.00$

9. $119 croquet set; 50% discount

You should not have problems with this: 50% discount means that you will pay half the price.

Hence, the sale price is:

$Sale\text{ }price=Orignal\text{ }price/2 \\\\ Sale\text{ }price=\$59.50$

10. $14.99 clock; 10% discount

$Sale\text{ }price=Orignal\text{ }price\times factor\\ \\ Sale\text{ }price=\$14.99\times(1-0.10)=\\\\ Sale\text{ }price=\$14.99\times0.90=\\\\ Sale\text{ }price=\$13.49$

11. A radio is on sale for $50. If this price represents a 10% discount from the original price, what is the original price to the nearest nickel? Hint: need to use a proportion to find the whole.

First note that if the discount is 10%, the sale price is 100% - 10% = 90% of the original price.

Let's set the proportion that represents the proportionality between the two ratios, starting with the fact that $ is the 90% and original price is the 100% (the whole part):

First ratio: $50/90

Second ratio: x /100

Proportion: first ratio = second ratio

$\$50/90=x/100$

Solve for x:

$x=100\times\$50/90=\$55.55$

Hence, the original price is $55.55

12. A box of laundry detergent is on sale for $6.50. If this price represents a 40% discount from the original price, what is the original price to the nearest cent?

Use the same hint used in the question above: set a proportion.

Remember a 40% discount means that the sale price is 60% of the original price:

$\$6.50/60=x/100\\ \\ x=100\times\$6.50/60=\$10.83$

13. Determine the price of a $35 basketball that is on sale for 50% off the regular price.

Again, 50% discount means that the sale price will be half of the original price, or the original price will be double of the sale price.

Here, the original price is $35, hence the sale price is $35/2 = $17.50

14. Dominic bought a new alarm clock that was on sale for $18.75. If this price represents a 30% discount from the original price, what is the original price to the nearest cent?

Since the price is after a 30% discount, the sale price is a 70% of the original price, and you set the proportion:

$\$18.75/70=x/100$

Solve for x:

$x=100\times\$18.75/70=\$26.79$

15. Michael bought a new fishing rod. The regular price of the fishing rod was $125.99. He bought it on sale with a 15% discount. Sales tax of 3% is applied to the discounted total. What was the sale price with tax of Michael’s fishing rod to the nearest cent?

First find the the sale price after the 15% discount:

$\$125.99\times(1-0.15)=\$125.99\times0.85=\$107.09$

Now add the 3% tax:

$\$107.09\times1.03=\$110.30$

Hence, the sale price with tax is $110.30

The last answer (# 16) is in the attached file, since this already exceeds the number of characters allowed.

7 0

4 years ago

At the start of 2014, tim house was worth £100,000 the value of the house increases by 10%per every year work out the value of h

kotykmax [81]

Answer:

$146410

Step-by-step explanation:

The formula for calculating future value:

FV = P (1 + r)^n

FV = Future value

P = Present value

R = interest rate

N = number of years

100,000 x (1.1)^4 = $146410

4 0

3 years ago