Heeeeelp! anyone good at maths...

[ElGuardiandenoche]

and can help with this question?

James has organised a game to raise
money for charity at a local fair.
He rolls a fair 6 sided dice and flips a fair coin.
If the coin lands on heads, the number
on the dice is squared.
If the coin lands on tails, the number on
the dice is cubed.

Each person pays 50p to play.
If they score over 30 they win a £1.
The game is played 450 times.

How much money does James raise for
charity.

Answers on a postcard please. It's 40 years since I left school and I only did CSE Arithmatic and I really can't work out the process with this one.

I’d just do a listing of all the possibilities - there’s only 12 of them. Then work out the expected number of payouts, and subtract 450*50p in income.

Just googled the text

Can you see it?

I would get them to work out all the possible different scores using a table. Eg
1 and H scores
2 and H scores etc...

Then count how many of the 12 results score over 30 and divide by 12. This will give you the probability of winning.

If the game is played 450 times, the total paid in will be 50p x 450.

You can only estimate how many times people will win. It will be the probability of winning each time multiplied by 450. Each win costs £1 so to work out the profit, subtract this from the money paid in.

Hope that helps.

Guess who should be working

Ok so chance of scoring over 30 is what?

Doubled, cubed
1 = 1,1
2= 4,8
3=6,9
4=8,16
5=10,25
6=12,36

So only one combination can win.
Chance of that combination is 1 in 12.

Games played 450 times = £225 minus times won.

1 in 12 per 450 is 8.3% of 450 = 37.35

You cant win a .35 time so it would be 37 wins.

So 225 - 37 = 188

So he raised £188

...... I think!

Waiting for someone smarter to come along!

Oops I did squared

Yes, I’d just work out the possible scores. There are 12, 8 are under 30 and 4 are over 30. He makes £225 (450 lots of 50p) and has to pay out £150 (1/3 of the players of 450 games will make £1) so the profit is £75.

@magis you haven’t squared and cubed your numbers correctly.

Your maths is spot on Magis, but in the time-honoured tradition of GCSE students you need to read the question more carefully

It is very handy that CorbettMaths uploads the answers. Some websites don't.

@IDefinitelyHaveFriends yeah I am a dick!

Thanks everyone for your help. We can now go forward.

I'd work out the probability of scoring over 30. Don't make me do the maths on that.

His takings are 225 pounds.
So the probability of scoring over 30, expressed as a percentage of 450 and subtract that number from the 225.

Makes sense in my head lol.

He’s read it and said ‘Ohhhhh! Yeah! I think I get it now.’

He’s just on his lunch break and then will get back to it and hopefully will come up with the right answer but at least I can now sit beside him and talk him through the process if needed.

You are all absolute stars ⭐️

I think it's only 4 and above on the dice that would score over 30. And 4 squared wouldn't pay out, neither would 5 squared.
So only 4 cubed, 5 cubed and 6 squared and 6 cubed would pay out.
So then...
Oh wait, my fucking head hurts lol

Am I right in thinking they've 4 chances out of 12 possible combinations that will pay out, so 1/3 of 450 which is 150
His takings are 225 - 150 he pays out in winnings, so the answer is his profit would be £75?

1 2 3 4 5 6
H 1 4 9 16 25 36
T 1 8 27 64 125 216

so 2 in 12 combinations result in a payout, which is one in 6

450 goes = £225 income
450 / 6 = £75 paid out

profit = £150

You're not looking at options for squared and cubed PlainJane

Oh you are
36 64 125 216 pay out
So FOUR not two pay out

Sorted! Thanks Everyone.

@tutorwho*@Teddypops the question set by the teacher was actually slightly different from the Corbett Maths one which confused me for a while until I realised. In the end I used @NotInTheMorning* explanation and got him to do the table from Corbett (on his own not copying) and then used leading questions to get him to think about it as per Not’s explanation.

Thank you once again you fabulous lot ⭐️ ⭐️

Far more interesting than my current work task!

@ElGuardiandenoche What answer did you come up with?

His answer was £75 but he did it again after submitting and came back with £150 so he's a bit muddled. He's hoping to get some feedback from

his teacher.

That was fun. I get £75 too.