Mathematics: Discussion, Questions & Potential Solutions

[horse9996]

It's 1.04ⁿ/1.05ⁿ
Then, you do (1.04/1.05)ⁿ because it's a common power
Then multiply by 100/100 and you get (104/105)ⁿ

But if you times the LHS by 100, don't you have to times the right as well?

[jasn9776]

What method did you guys use to get 5/27 did you just do 20/36*average probability by adding them up and dividing by 20. Or was there an easier method?

[Blissisignorance]

But if you times the LHS by 100, don't you have to times the right as well?

You're doing (1.04x100/1.05x100)ⁿ as 100/100=1, so you're just basically multiplying it by 1.

[parallaxd]

What method did you guys use to get 5/27 did you just do 20/36*average probability by adding them up and dividing by 20. Or was there an easier method?

I literally just summed up every situation. This was my working -> 2(1/36(1/6+2/6+3/6+4/6) + 1/36(1/6+2/6+3/6) + 1/36(1/6+2/6+1/6))

[fun_jirachi]

What method did you guys use to get 5/27 did you just do 20/36*average probability by adding them up and dividing by 20. Or was there an easier method?

I did it by cases. So basically there were 20 different cases.
8 had one number in between, so pulling a win (for one combo) would have the probability 1 in 6.
6 had two numbers in between, so pulling a win (for one combo) would have the probability 1 in 3.
4 had three numbers in between, so pulling a win (for one combo) would have the probability 1 in 2.
2 had four numbers in between, so pulling a win (for one combo) would have the probability 2 in 3.
So the total probability was

Which wouldve gotten you your 5/27.

[horse9996]

You're doing (1.04x100/1.05x100)ⁿ as 100/100=1, so you're just basically multiplying it by 1.

Oh yea that makes sense. Oh well! I think I did really well overall so one mark won't mean too much

[infectmarshroom]

Anyone know any links for worked solutions yet?

[fun_jirachi]

I highly doubt it, unless Jamon will post his solutions later today/sometime soon. After all, it's only been just under 6 hours since the conclusion of the exam.

[gershadev]

Honestly it would be great to have the solns right now

[RuiAce]

Sorry guys, would've done solutions for you but I haven't been able to obtain a copy of the 2U paper to do so :/

[Ellielh]

Someone posted a copy of the answers on the hsc discussion page. I'll see if I can download it.

Edit: https://drive.google.com/file/d/1Jf5WULe618G0fI5sREq2o7c5HrIDcuoo/view?usp=sharing

Here is the link to it. Tell me if it doesn't work.

#ripmymathsmarks

[Sheeplamb47]

Hang on, with those 2U solutions for question 13 c ii) (The population in 2020 one), they've used 100 years from 1910, when 2020 is 110 years from 1910. I might be wrong, but could someone please check that, I got 424 million or something

[MrBarbour]

Does anyone have a link or file to the Questions for this year's Paper?

[Ellielh]

Hang on, with those 2U solutions for question 13 c ii) (The population in 2020 one), they've used 100 years from 1910, when 2020 is 110 years from 1910. I might be wrong, but could someone please check that, I got 424 million or something

I got 424 million as well by using 110 years. I think (hope) the solutions are incorrect. A couple other people in the group said they got 424 mil as well.

[Sheeplamb47]

Okay, thank God, I hope so. Their working doesn't even work to get the answer they show. Hoping it's incorrect