Hi!

One of the questions that comes up EVERY YEAR is "Is it possible to go up X points from the mocks?" I want to do a poll on results day to get some sort of a measure for this for next year. I'm making an announcement about it to encourage ye to look for it on Friday.

I can only have 6 options, and 1 of those has to be "I just want to see the results" or people that just want to see the results will bias the poll. Thanks Reddit.

The question will be:

Did you get more points in the LC than in the mocks?

And the options will be:

* I got fewer points in the LC than the mocks

* I went up <= 30 points

* I went up more than 30 and <= 60 points

* I went up more than 60 and <= 90 points

* I went up more than 90 points

* I just want to see the results

Welcome to feedback on the options!

Friend of the family is looking for a general operative in Dublin. He does building maintenance and renovations, e.g. putting in the odd bathroom or kitchen, some plumbing work. Looking for anyone willing to work, basically. Long term is better but I think he'd be happy to take someone for a summer. Hours are sensible. Comment or send me a DM if you're interested. Must be 18 or older.

Was that one for the books?

Seeing life through a different lens? Feeling electric? Too hot for you? All this talk of atomic particles got your head spinning? Other physics puns!?

Feeling an equilibrium or having a bad reaction?

Polish, Lithuanian and a bunch of others this morning!

Hi,

It looks like the increased popularity of the subreddit over the LC period has caused it to be advertised to Irish redditors in general, so we've had a wave of gobshites wandering in. This has led to some confrontations that have led to the adults and some students being banned. I've stated the standards for adults in comments a few times but I've formally added a rule now.

Adults Must Be on Best Behaviour

> r/LeavingCert is a space primarily for students, with parents and teachers also welcomed. If you are not a recent Leaving Cert graduate then you are expected to behave yourself better than the students. Please be kind and helpful. Any adults being argumentative, rude, condescending, or trolling will be promptly banned. Sometimes the kids are wrong and confident about it. You were the same, just leave the conversation.

If you see someone who has no business being here being a dickhead please just report it. I'll take care of it. For the love of **** please don't call people "nonces" or "pedos" just for being an old gobshite. The rule about abuse will still apply and you will still be banned. I can't just ignore that behaviour because it festers. If they're being a prick just report it and leave the conversation.

Lamp

I hope this was easier for ye!

concept 1

Basic probabilities is just counting.

You roll a dice... What's the probability of a 3? There's a single way to get a 3 and six possible outcomes. So the probability is 1/6.

What's the probability of getting a number greater than 4? There's two ways for that to happen, 5 & 6, and 6 possible outcomes so the probability is 2/6 = 1/3.

concept 2

All probabilities add up to 1, i.e. calculating NOT outcomes

What's the probability of NOT getting a 3? Well there's 6 possible outcomes, one of them is 3 and five of them are not 3. The probability is 5/6.

1/6 + 5/6 = 6/6 = 1, or more usefully... 5/6 = 1 - 1/6

So if you can calculate the probability of something happening then you also get the probability of it NOT happening. It's just 1 - the opposite.

concept 3

OR is addition

What's the probability of getting an even number? 3 ways... 2 or 4 or 6... By the principle of counting above that is probability of 3/6, which is 1/6 + 1/6 + 1/6.

Note that this is for independent results, things that can't happen at the same time. E.g. what's the probability of an even number OR a number that is a multiple of 3 then it's more complicated because 6 is both even and a multiple of 3. By counting, we know the probability of that is 4/6 but if you just add 3/6 (prob of even) and 2/6 (prob of multiple of 3) naively you would get 5/6 which is wrong.

concept 4

AND is multiplication.

If you roll 2 dice there are 36 combinations. That's 1 and 1, and 1 and 2 etc etc up to 6 and 4, 6 and 5, 6 and 6. What's the probability of a 6 on the first dice? That's 6/36 = 1/6. What's the probability of 6 on the second dice? That's 6/36 = 1/6. What's the probability of 6 on both dice in the same roll? That's 1/36 = 1/6 * 1/6. Again like for OR this is for independent events.

What's the probability of one even number and a 5? This is a hard one because it combines AND and OR. It could be (even on the first die AND 5 on the second) OR (5 on the first die AND even on the second). So it's (3/6 * 1/6) + (1/6 * 3/6) which is coincidentally just 1/6.

concept 5

Picking multiple things from 1 pile (without putting them back) is a like running consecutive AND trials.

It ends up looking like factorial calculations and can be calculated using binomials (n C r).

E.g. if you have 4 black balls and 3 red balls in a hat, what's the probability of drawing 3 black balls?

Well the probability of the first black ball is 4/7

The second is 3/6 (cos you've removed a black ball)

The third is 2/5 (because you've removed 2 black balls)

First AND second AND third is

4/7 * 3/6 * 2/5 = (4*3*2) / (7*6*5)

We can actually jump straight to this with a binomial calc by calculating (the number of ways to choose 3 black balls from 4 black balls) / (the number of ways to choose 3 balls from 7), which is (4 C 3) / (7 C 3). Which works out the same!

Just wanted to say that making negative posts about specific users is not ok, especially if that user's name or sufficient comment quotes to find them are included. Drawing a lot of attention to a person with an unpopular or hard to explain opinion can be very stressful to that person, and often they are not in a position to defend themselves against a mob-like public shaming. We're not talking about politicians or celebrities here, just some rando on the internet without a publicist. And randos on the internet can sometimes be wrong and we shouldn't try to ruin their week about it. Especially not _this_ week.

Anyway, please do not make call out posts. They will be treated as harassment going forward.

How are those bonus points looking?