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
6

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

Mathematics
1 answer:
nignag [31]3 years ago
7 0
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.
You might be interested in
What is the area of the figure?
AysviL [449]

Answer:

C

Step-by-step explanation:

3 0
3 years ago
Im bad at money :/ do please help me
Semenov [28]

The third answer

1 quarter, 6 dimes, 1 nickel, 7 pennies

6 0
2 years ago
Fay has a lemonade stand.
AnnyKZ [126]

Answer:

her total profit is 3

Step-by-step explanation:

1.50 x 30 = 45

to find total profit - 45-42= 3

5 0
2 years ago
Read 2 more answers
Hey You <br> YES YOU CAN ANSWER THIS PLEASE<br> solve for T: 4 j= -9T
OLEGan [10]
-9T means -9 x T
So if T is equivalent to 4,
you should do:
-9 x 4 = -36
J= -36
8 0
3 years ago
a store had 600 pounds of feed. after delivering equal amounts to 4 farmers , there are 60 pounds left. how many pounds did each
Daniel [21]

Answer: 135 pounds

Step-by-step explanation:

600-60=540

540/4=135

6 0
2 years ago
Other questions:
  • What is the value of p?
    5·1 answer
  • Which of the following is equal to <img src="https://tex.z-dn.net/?f=%20%5Cfrac%7B1%7D%7B5%5E2%7D%20%20" id="TexFormula1" title=
    8·1 answer
  • Find b and c so that (5,b,c) is orthogonal to both (1,2,3) and (1,-2,1)
    8·2 answers
  • What is the distance between 17 and 31 on a number line
    7·2 answers
  • Which expression is equivalent to the following complex fraction?
    5·1 answer
  • Can 7 over 63 be simplified
    12·2 answers
  • Algunos numerod irracionales tienen representacion decimal infinta y periodica .<br>​
    9·1 answer
  • Is an estimate of 28,000 over or under the actual product of 365 and 68? How can you tell? over; because both were rounded up ov
    7·1 answer
  • A truck can be rented from Company A for ​$100 a day plus ​$0.50 per mile. Company B charges ​$40 a day plus ​$0.80 per mile to
    7·1 answer
  • 1. What is the measure of angle x? O 60° O 90° O 45° O 30°​
    13·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!