Rating: 5.0

# Plaid CTF 2014: multiplication is hard

**Category:** Misc
**Points:** 10
**Description:**

> The Plague went back in time... but we haven't yet figured out what he did this time... Anyway, what is 38.55 * 1700?

## Write-up

Mathematically, `38.55 * 1700 = 65535` but that solution was not accepted.

Years ago (“back in time”), [Excel used to have a bug](http://blogs.office.com/2007/09/25/calculation-issue-update/) where calculations that resulted in a number close to 65,535 would instead show a result of 100,000.

The flag is `100000`.

## Other write-ups and resources

* <https://github.com/hackerclub/writeups/blob/master/plaidctf-2014/multiplication-is-hard/WRITEUP-pipecork.md>
* <http://csrc.tamuc.edu/css/?p=152>

Original writeup (https://github.com/ctfs/write-ups/tree/master/plaid-ctf-2014/multiplication-is-hard).