At a party, everyone shook hands with everybody else. There were 66 handshakes. How many people were at the party?

Answers

Answer 1

Answer:

66?lol

Step-by-step explanation:

Answer 2

Answer:

12

Step-by-step explanation:

In general, with n+1 people, the number of handshakes is the sum of the first n consecutive numbers: 1+2+3+ ... + n.

Since this sum is n(n+1)/2, we need to solve the equation n(n+1)/2 = 66.

This is the quadratic equation n2+ n -132 = 0. Solving for n, we obtain 11 as the answer and deduce that there were 12 people at the party.

Since 66 is a relatively small number, you can also solve this problem with a hand calculator. Add 1 + 2 = + 3 = +... etc. until the total is 66. The last number that you entered (11) is n.

hope this helped i had this same question and i answered it


Related Questions

Examine the equation. –3x + 18 = 7x What could you do to isolate the variable term to one side of the equation? Add 3x to both sides. Subtract 3x from both sides. Add 18 to both sides. Subtract 18 from both sides.

Answers

Answer:

You would add 3x to both sides. Then divide by 10 on both sides.

What to do to isolate the variable term to one side of the equation is to add 3x to both side

Given the equation, -3x + 18 = 7x, we need to isolate the variable term. To do that, we will follow the steps below;

Add 3x to both sides of the equation to have;

-3x + 18 + 3x = 7x + 3x

18 = 7x + 3x

Swap sides

7x + 3x = 18

10x = 18

Divide both sides by 10

10x/10 = 18/10

x = 1.8

From the steps above, what to do to isolate the variable term to one side of the equation is to add 3x to both side

Learn more here: https://brainly.com/question/14107099

Lauren is sewing a quilt using fabric squares.

The length of a side of a fabric square is represented by the expression x + 4.
Which expression represents the area of a fabric square?

4x + 6
2x + 8
x + 4
x2 + 8x + 16

Answers

Answer:

x^2 + 8x + 16

Step-by-step explanation:

Given length of square x + 4.

Area of square with side S is given by [tex]S^2[/tex].

Therefore are of square with side x + 4 is given by [tex](x + 4)^2[/tex]

Area of square = [tex](x + 4)^2\\=>(x + 4)*(x + 4)\\=> x(x + 4) + 4(x + 4)\\=> x^2 + 4x + 4x + 4*4\\=> x^2 + 8x + 16[/tex]

Thus, x2 + 8x + 16 expression represents the area of a fabric square.

Haruto has tomato plants in his backyard. This year the plants grew 127 tomatoes. Birds had eaten 19 of the tomatoes. 23 tomatoes had been ruined by bugs. He picked the rest. How many tomatoes did Haruto pick? The answer is tomatoes.

Answers

Answer: 85 hope this helped!

The spray from a sprinkler reaches 21 feet from the sprinkler and creates a circle as it spins. What is the circumference of the circle sprayed by the sprinkler? Use
22
7
for π.
21 ft
66 ft
120 ft
132 ft

Answers

Answer:

D: 132 ft

Step-by-step explanation:

C= π2r

So, take pi and multiply that by two..

π2= 6.28

Now, take your radius and multiply it by 6.28.

21 x 6.28= 131.88

Round it two the nearest whole number, which is 132!

Hope this helps!

Answer:

132

Step-by-step explanation:

How do I calculate this parent function of a linear function? The parent function of a linear function is y=x. When the parent function is changed to y=x+5, how does the graph transform?

Answers

Step-by-step explanation:

This only moves the linear function up 5 units. So, before the y-intercept and the x-intercept both was (0,0). Now, the y-intercept is (0,5) because the graph was shifted up 5 units.

hope this helps :)

john wants to buy a new phone for 1200. the sales tax is 8.875%. what is the total price?

Answers

Answer:

$1306.50

Step-by-step explanation:

1200(1 + tax) = total price -->

1200(1.08875) = total price -->

1306.5 = total price

Can u guys pls help this is due in 2 mins!

Answers

-3x + 3y = -18

-x + y = -6

-2x + 2y = -12

5x - 2y = 9

Adding,

3x = -3

x = -1

y = -6 +x = -6 - 1 = -7

Answer: B. (-1, -7)

Answer:

B

Step-by-step explanation:

Find the area of the shape

(sorry if im asking too many questions)

Answers

Answer:

E. 54

Step-by-step explanation:

To find the area just multiply the base times the height. In this problem it would just be 6x9= 54.

Answer:54 cm ^2

Step-by-step explanation:

9 times 6 is 54

Find the lateral area and surface area of a regular hexagonal right prism is the base edges are 10 and the height is 12.


Round your answer to the nearest tenth.



LA = units squared


SA = units squared

Answers

Answer:

Step-by-step explanation:

a hexagonal prism is made up of two bases that are hexagons and six faces that are rectangles.

Lateral surface area, LA = Perimeter × height

Perimeter = number of sides × length of each side

Perimeter, P = 6 × 10 = 60

LA = 60 × 12 = 720 units squared

Area of each base, B = 1/2a × perimeter

Where

a = apotherm

We would determine the length of the apotherm of each base of the prism by applying the formula,

a = s/[2tan(180/n)]

Where

s = length of each side = 10

n = 6 sides

a = 10/[2tan(180/6) = 10/[2tan30)

a = 8.66

B = 1/2 × 8.66 × 60 = 259.8

Total surface area = LA + 2B

Total surface area = 720 + 2 × 259.8 = 1239.6 units squared

Kia is saving money to buy a Six Flags ticket. She worked for 6 hours at the library and earns the same amount each hour. Her grandmother then gave her $20. In all,she has $53.

Answers

Answer:

She earns 5.5 dollars per hour at the library

Step-by-step explanation:

I am going to assume that the questions is "how much she earns per hour at the library?"

Let's call x the amount of dollars earn by hour at the library. We know that she worked for 6 hours, thus she made 6x dollars.

Later her grandma gave her 20 dollars and she has now 53 dollars.

Let's write the equation and solve it

Amount earned + Amount given by her grandma = 53

[tex]6x+20=53\\6x=33\\x=\frac{33}{6}\\x=5.5[/tex]

Thus, based on this information we would have that Kia earns 5.5 dollars per hour.

Find the surface area.

Any help will be appreciated thank you!

Answers

Answer:

580 cm^2

Step-by-step explanation:

H = Height

L = length

W = width

2(HL)+2(WH)+2(WL)

= 2(20*10)+2(3*20)+2(3*10)

= 2(200)+2(60)+2(30)

= 400+120+60

= 580

5m + 9n if m = -7 and n = 4

Answers

Answer:

1

Step-by-step explanation:

5m + 9n

5(-7) + 9(4)

-35 + 36

1

Answer:

1

Step-by-step explanation:

5m + 9n

Plug in the numbers

5(-7) + 9(4)

Multiply

- 35 + 36

Solve.

36-35=1

Please help ASAP....

Answers

Answer:

7 is D and 8 is D

Step-by-step explanation:

I'm assuming you were asked for the volume of both of these.

7. The area of the trapezoid is 18 then multiply by the length of 8 to get 144 units cubed.

8. The area of the trapezoid is 28 then multiply by the length of 14 to get 392 units cubed.

The amount of money that Li spends on video games depends on how
many games he purchases. If Li has at most $90 to spend on games for his
Xbox 360 and the games cost $22.50 each, what is the domain of this
function?

Answers

Answer:

x < 4

Step-by-step explanation:

The function is represented by this equation:

22.5x = y

Where x is the number of games he buys and y is the amount of money that he spends. We know that y cannot be greater than 90, because Li only has 90 dollars. So, if y is less than 90, 22.5x must be less than 90 as well.

22.5x < 90

x < 90/22.5

x < 4

Write an inequality for each sentence.
The elephant weighs more than 12,000 pounds.

Answers

Answer:

e > 12000 pounds

Step-by-step explanation:

Since the elephant weighs over 12000 pounds it would not be greater than or equal to or less than or less tan or equal to so

if elephant = e than

e > 12000 pounds

A given line has the equation 10x+2y=−2 .

What is the equation, in slope-intercept form, of the line that is parallel to the given line and passes through the point (0, 12)?

Answers

Answer:

Step-by-step explanation:

2y = -10x - 2

y = -5x - 1

y - 12 = -5(x - 0)

y - 12 = -5x + 0

y = -5x + 12

-9x+3y=-30 in slope intercept form

Answers

Answer:

y = 3x - 10

Step-by-step explanation:

Answer:

y = 3x -10

Step-by-step explanation:

Slope intercept form is y = mx+b  where m is the slope and b is the y intercept

-9x +3y =-30

Add 9x from each side

-9x+9x +3y =9x-30

3y = 9x-30

Divide each side by 3

3y/3 = 9x/3 -30/3

y = 3x -10

How do I Graph y=-2x+5

Answers

Answer:

Slope-Intercept Form y = mx + b

Y = 5

Slope = -2/1

Step-by-step explanation:

Slope-Intercept Form y = mx + b

m = Slope; Rise over Run; Remember there is always an understood 1 in the denominator. If the slope is positive it goes up and to the right and if the slope is negative it goes down and to the right.

b = Y-intercept; This is where the line crosses the y-axis at. If it's positive it's above the x-axis and if negative below.

Help asap! giving brainliest!

Answers

Answer: understand The problem

Gather reasources

check your answer to a solution

come to an answer

Mica and Denise are reading the same novel. Mica has read 1/2 of the novel, and Denise has read 2/5 of the novel. If Mica has read 216 pages more than Denise, how many pages are totally for this novel?

Answers

Answer:

The novel has 2160 pages.

Step-by-step explanation:

The number of pages of the novel is x.

Mica has read 1/2 of the novel, so x/2 = 0.5x.

Denise has read 2/5 of the novel, so 2x/5 = 0.4x.

Mica has read 216 pages more than Denise

This means that:

0.5x - 0.4x = 216

0.1x = 216

x = 216/0.1

x = 2160

The novel has 2160 pages.

The owner of a coffee shop compared the amount of hot coffee per day, in fluid ounces, sold and the daily high temperature, in degrees Fahrenheit, per day. Her data are shown in the scatter plot below. If these data are modeled by the line y = -5.9x + 850, which statement best describes a valid prediction the owner could make?

Answers

Picture of the question is attached below.

Answer: B.) For each temperature decrease of 10°F, the shop can expect to sell about 6 fluid ounces more of hot coffee.

Step-by-step explanation:

The model depicted by the line equation:

y = -5.9x + 850 shows a strong negative linear relationship between the amount of hot coffee per day, in fluid ounces, sold and the daily high temperature, in degrees Fahrenheit, per day. This means that the sale of hit coffee decreases with increasing temperature daily, which makes sense. From the plot and line model equation, the shop can expect to sell about 6 fluid ounces less of hot coffee for each temperature ruse of 10F.

-5.9x approximately -6x decrease for every 10F temperature increase.

1 1/7 times 3/5 plz answer now

Answers

Answer:

24/35 or 0.6857142

Step-by-step explanation:

Answer:

[tex] \frac{24}{35} [/tex]

alternative form:

[tex] 0.685714286 [/tex]

Step-by-step explanation:

[tex]1 \frac{1}{7} \times \frac{3}{5} \\ multiply \: 1 \: and \: 7 \\ \\ \frac{7 + 1}{7} \times ( \frac{3}{5} ) \\ add \: 7 \: to \: 1 \\ \\ \frac{8}{7} \times ( \frac{3}{5} ) \\ remove \: parenthesis \: and \: put \\numerator \: times \: numerator \: and \\ denominator \: times \: denominator \\ \\ \frac{8 \times 3}{7 \times 5} \\ do \: the \: multiplications \\ \\ \frac{24}{35} [/tex]

help me fill this out thanks

Answers

Answer:

10

Step-by-step explanation:

We cannot use the Pythagorean Theorem here because we only have one side length. However, we can use the fact that [tex]\frac{a}{sin(A)} =\frac{b}{sin(B)}=\frac{c}{sin(C)}[/tex]

I decided to make the corner with the 60° as ∠A, the corner with the 30° as ∠B, and the corner with the right angle as ∠C. While then making side a as the unmarked side, side b as the side with 5, and the hypotenuse p as side c.

Since we do not need to solve for a in this equation to solve for p, we can simply use the sides and numbers we are given.

Manipulating two of our equations, preferably the equations with the variables b and c, we can get [tex]\frac{b}{sin(B)}=\frac{c}{sin(C)}[/tex] and solving for c, which is p in this case, will give us [tex]c=\frac{bsin(C)}{sin(B)}[/tex]

Plugging in the numbers we have gives us [tex]c=\frac{5sin(90)}{sin(30)}[/tex] = 10 mi

Correct answers only!

To the nearest cent, how much will he have in 2 years?

Use the formula B = p(1 + r)t, where B is the balance (final amount), p is the principal (starting amount), r is the interest rate expressed as a decimal, and t is the time in years.

Answers

Answer: $44.10

Step-by-step explanation:

We are given our p, r, t in the problem.

p=40 (starting amount)

r=0.05 (5%)

t=2 (years)

With the given information, we can plug this into our equation.

B=p(1+r)^t

B=40(1+0.05)^2

B=44.1

What is the volume? Please answer asap.

Answers

Answer:

20

Step-by-step explanation:






I am Giving 50 points
Hailey organizes a New Year’s party. There are 16
pastries at the party, 7 of the pastries
are chocolate. What is the relative
frequency probability that a randomly
selected pastry will be a chocolate
pastry?

Answers

7/16 maybe

...............

Answer:

7/16

Step-by-step explanation:

the relative

frequency probability that a randomly

selected pastry will be a chocolate

pastry is 7/16


Which of the following fractions is equivalent to 3/5 ?
A 1/2
B 3/8
C 6/20
D 9/15

Answers

The answer is D :).

Explain how to decide which is a better value. 4 greeting cards for $10 and 6 greeting cards for $14.

Answers

Answer:

I dont know if this is supposed to be solved a certain way for a class, but as a bargain shopper, this is what I would do to figure out the best value.

Step-by-step explanation:

First divide $10 by 4:   10.00/4=2.5 or $2.50 per card

Then, divide $14 by 6:  14.00/6=2.3333333 so about $2.33 per card

Now, just look at the two answers and see which one is less.

If you buy 4 cards for $10, you will pay $2.50 for each card and if you buy 6 cards for $14, you will pay about $2.33 for each card. Therefore, the better value would be the 6 cards for $14.

Hi can some1 help me for q3 only.. thanks!! If possible please help for q4 too!!

Answers

3. a) i) For the first two years,
P=$25000
R=0.3%
T=2 years
I=(PxRxT)/100
=(25000x0.3x2)/100
=$150
For the remaining three years,
P=$25000
R=0.5%
T=3 years
I=(PxRxT)/100
=(25000x0.5x3)/100
=$375
Amount of interest he receives for 5 years=375+150=$550

ii) P=$25000
R=0.4%
T=3/12=1/4=0.25 year(The time,t is measured in years)
I=(PxRxT)/100
=(25000x0.4x0.25)/100
=$50
In 5 years, there are 5x12=60 months
For every 3 months, he receives $50
For 60 months, he receives (50/3)x60=$1000

b) Mark should choose to invest in UOO bank as he receives 1000-550=$450 more in the form of interest.

For number 4, please check this photo:

evaulate 3z when z is =9

Answers

[tex]\text{Plug in and solve:}\\\\3z\\\\3(9)\\\\\boxed{27}[/tex]

Answer:

27

Step-by-step explanation:

3z       z=9

3 times 9

27

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