Unprotected Sex!

The odds that a Pregnancy will result from a Single Act of Unprotected Sex are approximately 1 in 25 (0.04%)

Don't let this be YOUR future child...

Whoa, kids. I know what you're thinking. Hot shit! I can have unprotected sex twenty-four times scott-free before I even have to worry!

Well, sorry to burst your idiot bubble but if you think that then
1) you suck ass at math and have no idea how probability works
2) you should start thinking of names for the idiot child you're about to have (I'ma call him Biff)

For the rest of you, let's break this down.

Basically this is an issue of timing. Now, full disclosure: I'm not a scientist but I have it on good authority that boys have penises and girls have vaginas. Now, to make babies... I don't know, but a woman can only get pregnant on approximately 2 days in every 28 of their cycle. But then she also needs a dude's spermatazoa to eat the egg or whatever and those little fuckers can only survive for around 2 days once in her stomach. This gives us odds of jot, scratch, erase = 11%!

But even if these two windows do happen to overlap after your shitty Junior Prom in the back of that shitty Pinto, there's some good news: Sometimes the spermatazoa don't always eat the eggs! In fact, when together they only do their thing 1/2 to 1/4 of the time they're all chilling. This drops the odds down to between 3-5% that you'll have to explain to your son (Biff) that he was the result of a drunken irresponsible and horribly awkward night for everyone.

Seriously though, 3-5% is a lot. Like 85% odds in the first year if you keep at it, but whatever, it's your life to roll the dice with. Consider yourself warned so don't bitch to me when you're rail-roaded into marrying said girl you brought to J-Prom who now resents you cause you got her preggers (and you didnt't even wanna go with her!) and then have an idiot son named Biff who sucks at math. Good luck with that though.

(http://wiki.answers.com/Q/What_are_the_odds_of_getting_pregnant_if_you_had_sex_only_one_time)

Climbing Everest!

The odds that you will die as the result of Attempting to Summit Mount Everest are approximately 1 in 61 ( 1.6%)

Now, I'm not a climber, but it seems to me that you're asking for trouble when you decide to climb 29,000 feet (~ 6 miles) above sea level so you can stand on top of a freezing cold mountain and look at....other mountains. If you wanna 'push' yourself, rent 'Cliffhanger' and do that instead. At least it won't be so cold and you'll look so much cooler hanging over a valley by one arm in a wifebeater.

Also- climbing Everest doesn't count if you pay $25,000, suck down pure oxygen the whole time in your kevlar parka, and pay local sherpas to tell you where to go and carry all your shit up the mountain. Gotta do that shit freestyle in some Keds like Sir Hillary. Sorry, bitches.

(http://www.bookofodds.com/Daily-Life-Activities/Hobbies-Recreation/Odds/The-odds-a-person-climbing-Mt.-Everest-will-die-in-the-attempt-are-1-in-61.46-CN-IN-and-NP-1950-2006)