# Find the next number [closed]

"I will, of course, kill you if you don't answer. But that's a given, isn't it?" The Enemy says. "So come, Zero, and show me your legendary brain."

$2.828,\quad5.196,\quad11.180,\quad18.520,\quad x$

What is $x$?

C2L, Part 1.

## closed as off-topic by Engineer Toast, JonMark Perry, Rubio♦Mar 7 '18 at 17:15

• This question does not appear to be about creation and solving of puzzles, within the scope defined in the help center.
If this question can be reworded to fit the rules in the help center, please edit the question.

• What is "C2L, Part 1" ? – Rubio Mar 5 '18 at 17:31
• @Rubio Part 1 of a series of puzzles I'm going to give. – Buddha Mar 5 '18 at 17:39
• @Buddha you should probably cite your source, which seems to also be the TORN forums: torn.com/… – Quintec Mar 5 '18 at 18:56
• This question does not appear to be about creation and solving of puzzles, within the scope defined in the help center. – Engineer Toast Mar 7 '18 at 16:25

## 1 Answer

The answer is

$36.482$ or $36.483$ depending on whether the numbers are truncated or rounded at 3 decimals.

Explanation:

The numbers are $2 \sqrt{2}$, $3 \sqrt{3}$, $5 \sqrt{5}$, $7 \sqrt{7}$ where $2$, $3$, $5$, $7$ are successive primes. The next prime is $11$ to give $11 \sqrt{11}=36.4828726...$.

• How do you find this answer? I mean I have no idea how a person can think like this? – I am the Most Stupid Person Mar 6 '18 at 3:58
• @IamtheMostStupidPerson I guess it's because it has to follow some fixed rule that you can try out. Also, prime numbers are always popular. So you could try different combinations of prime numbers, once you found out how the first number came to be. Another possibility is, that you actually know what $2.828$ is because you have used it at school, at work etc. and start working your way up from there. For instance, I work as a developer and $\sqrt{2}=1.414$ appears quite often in my tasks, so it's useful to remember the decimal value. Then you can immediately see the connection to $2.828$. – QBrute Mar 6 '18 at 6:38
• Yes, for me $2.828$ was a dead give-away. On a hunch I then divided the next number by $3$, recognised the result, and the rest followed. – Jaap Scherphuis Mar 6 '18 at 7:29