At a party, everyone shook hands with everybody else. There were 4005 handshakes. How many people were at the party?
The number of handshakes between people is always the sum of 1+2+3+...+(n-1). n = number of people. Say there are 5 people, handshake between them will be 1+2+3+4 = 10 (try that with your friends 😀)
The sum of 1 to n of any number is (n(n+1))÷2. For example 1+2+3+4+5 = 15 and (5(5+1))÷2 = (5*6)÷2 = 15
So, to find the number of people at the party
(n(n+1))÷2 = 4005
Cross multiplying: n(n+1) = 4005x2 = 8010
Expanding the bracket: n² + n = 8010 n² + n - 8010 = 0
Solving that using the Almighty Formula (I don't think I need to go into that details)
n = 90 and -89
Ofcourse there can be negative people at the party so answer is 90 people
At a party, everyone shook hands with everybody else. There were 4005 handshakes. How many people were at the party?
The number of handshakes between people is always the sum of 1+2+3+...+(n-1). n = number of people. Say there are 5 people, handshake between them will be 1+2+3+4 = 10 (try that with your friends 😀)
The sum of 1 to n of any number is (n(n+1))÷2. For example 1+2+3+4+5 = 15 and (5(5+1))÷2 = (5*6)÷2 = 15
So, to find the number of people at the party
(n(n+1))÷2 = 4005
Cross multiplying: n(n+1) = 4005x2 = 8010
Expanding the bracket: n² + n = 8010 n² + n - 8010 = 0
Solving that using the Almighty Formula (I don't think I need to go into that details)
n = 90 and -89
Ofcourse there can be negative people at the party so answer is 90 people
Answer: 90
BY Riddles Repository - Answers
Warning: Undefined variable $i in /var/www/tg-me/post.php on line 283
However, analysts are positive on the stock now. “We have seen a huge downside movement in the stock due to the central electricity regulatory commission’s (CERC) order that seems to be negative from 2014-15 onwards but we cannot take a linear negative view on the stock and further downside movement on the stock is unlikely. Currently stock is underpriced. Investors can bet on it for a longer horizon," said Vivek Gupta, director research at CapitalVia Global Research.
The SSE was the first modern stock exchange to open in China, with trading commencing in 1990. It has now grown to become the largest stock exchange in Asia and the third-largest in the world by market capitalization, which stood at RMB 50.6 trillion (US$7.8 trillion) as of September 2021. Stocks (both A-shares and B-shares), bonds, funds, and derivatives are traded on the exchange. The SEE has two trading boards, the Main Board and the Science and Technology Innovation Board, the latter more commonly known as the STAR Market. The Main Board mainly hosts large, well-established Chinese companies and lists both A-shares and B-shares.