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
Bitcoin mining is the process of adding new transactions to the Bitcoin blockchain. It’s a tough job. People who choose to mine Bitcoin use a process called proof of work, deploying computers in a race to solve mathematical puzzles that verify transactions.To entice miners to keep racing to solve the puzzles and support the overall system, the Bitcoin code rewards miners with new Bitcoins. “This is how new coins are created” and new transactions are added to the blockchain, says Okoro.
What Is Bitcoin?
Bitcoin is a decentralized digital currency that you can buy, sell and exchange directly, without an intermediary like a bank. Bitcoin’s creator, Satoshi Nakamoto, originally described the need for “an electronic payment system based on cryptographic proof instead of trust.” Each and every Bitcoin transaction that’s ever been made exists on a public ledger accessible to everyone, making transactions hard to reverse and difficult to fake. That’s by design: Core to their decentralized nature, Bitcoins aren’t backed by the government or any issuing institution, and there’s nothing to guarantee their value besides the proof baked in the heart of the system. “The reason why it’s worth money is simply because we, as people, decided it has value—same as gold,” says Anton Mozgovoy, co-founder & CEO of digital financial service company Holyheld.
