2001 HSC Ext1 Maths -- Q2 (c) part (ii) -- Permutations (1 Viewer)

[blackops23]

Quick question is the answer (5!)(4!)/2! = 1440 or (6!)(4!)/2! = 8640?

I did (6!)(4!)/2! --> but the solutions say (5!)/(4!)/2!? If the solutions are correct, can someone please explain why? I thought you were meant to treat the 4 vowels as 1 letter, so you would have 6 'letters' instead of 9 -- then 6! would be the no. of arrangements -- but vowels can rearrange themselves amongst each other in 4!/2! ways.... someone please explain thanks

 

[AAEldar]

Four positions but there are 2 A's, so that's where the 2! comes from, and then times 5! because of the 5 consonants.

 

[blackops23]

Also Q7 (a) part (ii) --> I got x = 1- e^(-t), however the solutions state x = 1 + e^(t), could some please check up on this?

Thank you!

 

[AAEldar]

Also Q7 (a) part (ii) --> I got x = 1- e^(-t), however the solutions state x = 1 + e^(t), could some please check up on this?

Thank you!

The answer is definitely , and the solutions I have match up with that.

 

[blackops23]

The answer is definitely , and the solutions I have match up with that.

^mind linking us with these solutions lol? I remember one of the solutions from this website: http://exampapers.web.fc2.com/ep/hsc.html#Extention 1 Solutions thought that 11-3 = 9.... and those are the only solutions I have access to.
EDIT: Just noticed, the website spells extension as extention.......................... -.-

 

[AAEldar]

^mind linking us with these solutions lol? I remember one of the solutions from this website: http://exampapers.web.fc2.com/ep/hsc.html#Extention 1 Solutions thought that 11-3 = 9.... and those are the only solutions I have access to.
EDIT: Just noticed, the website spells extension as extention.......................... -.-

I've got the MANSW book for 2001-2010, so I don't have them on my computer >.<

 

[D94]

o.0 Edit:

Since when , you take the as the initial equation, and solve that to get .