Search results

Re: 2015 permutation X2 marathon The probability they all go through one door is actually 1 / [n^(n-1)] Although you have my answer, I don't see how it follows from your first line.

Re: 2015 permutation X2 marathon See what happens with your answer when n=4.

That brings back good mammaries.

Ahh no - I have a reputation to protect.

Re: 2015 permutation X2 marathon The answer for anyone who wants to peek: 1 - n! / (n^n)

Does it apply to me?

Re: 2015 permutation X2 marathon Drsoccerball's solution is correct. 3!/2! = 3, and there most definitely is 3 ways to arrange 4,4,2 or 4,3,3. Another thought process (but same calculation): (For the 4,4,2 case): Pick the 2 first: 10C2 Pick the room for those two: 3 Pick one of the...

Re: 2015 permutation X2 marathon I can see your answer when I "reply with quote". It's hard to tell without proper formatting, but it seems to be correct.

Re: 2015 permutation X2 marathon * There are n balls in a bag, numbered with consecutive integers 1 to n. Show that the probability that if p balls are chosen that no chosen ball has number 1 to q is the same as the probability that if q balls are chosen that no chosen ball has number 1 to p.

From the board - "Pencil may be used only where specifically directed."

Hmmm - which top 5 school has 5 Ext 2 maths classes?

My wish is that before I die, every student will understand the moderating process. But of course I don't believe in miracles.

Why are you looking at worst case scenarios? Do you really think this scenario is possible if all 5 were so close internally?

Re: HSC 2015 3U Marathon You'd better read the question again - it's not asking for the highest velocity.

That's what I'm saying - OP has it correct.

Part (ii) doesn't need any calculation. The probability that the car is on the last level he happens to choose is clearly one in three.

Whoever provided the other solution had a valid method, but got their numbers wrong. The possible arrangements are: Vcccc cVccc ccVcc cccVc ccccV So the 4 times 3! for the vowels should have been 5 times 3!. They must have assumed 4 consonants equates to 4 places for the vowels - the...

OR .... you could pay for a copy and allow the authors to get the reward they deserve.

Hmmm - "impend" ??

Here is the solution: As you can see from the final answer, your choice of 2.4 was not ideal either - any lower and it would not have worked again (because 1.01375^64 is 2.396).