Maths Questions

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Rhys Benjamin
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Maths Questions

Post by Rhys Benjamin » Tue Sep 28, 2010 5:08 pm

3 friends are eating at a restaurant. The bill is £30 and they pay immediately, paying £10 each. The waiter then realises he made a mistake and should have charged £25. He takes £5 from the till to give it back, but on his way he decides to keep £2 as a tip and give each customer £1, since you can't divide 5 by 3. So, each customer ends up paying £9 plus the waiter keeps £2, making £29 in total. What happened to the missing £1?
Last edited by Rhys Benjamin on Wed Sep 29, 2010 7:24 pm, edited 1 time in total.
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Re: Maths Question

Post by Charlie Reams » Tue Sep 28, 2010 5:24 pm

Inflation.

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Re: Maths Question

Post by Matt Morrison » Tue Sep 28, 2010 5:33 pm

Do your own homework.

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Re: Maths Question

Post by JimBentley » Tue Sep 28, 2010 5:52 pm

It's because there's three different situations being used and the question pretends that all the situations are the same. From the customer's point of view, the meal initially cost £30, but then they believe that it actually cost £27, because that's what the waiter told them. From the restaurant's point of view the meal cost £25, which is the true situation. So the £30 becomes irrelevant once the waiter takes a fiver from the till. Something like that, anyway.

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Re: Maths Question

Post by Matt Morrison » Tue Sep 28, 2010 6:00 pm

You're too kind Jim.

In short, it's not "£9 from each customer and £2 for the waiter = £29", which when you think about it makes so little sense and is nigh-on impossible to even get your head round as a concept.
It's "£9 from each customer = £27, of which £2 goes to the waiter (and £25 to the till)".

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Re: Maths Question

Post by Rhys Benjamin » Tue Sep 28, 2010 6:01 pm

Oh, this isn't homework, something I saw in a book.
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Re: Maths Question

Post by James Hall » Wed Sep 29, 2010 11:04 am

Of the original £30, each of the three customers has £1, the waiter has £2 and the till has £25 - helps me to work out where all of the £30 went.
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Re: Maths Question

Post by Jon Corby » Wed Sep 29, 2010 1:51 pm

Rhys Benjamin wrote:3 friends are eating at a restaurant. The bill is £30 and they pay immediately, paying £10 each. The waiter then realises he made a mistake and should have charged £25. He takes £5 from the till to give it back, but on his way he decides to keep £2 as a tip and give each customer £1, since you can't divide 5 by 3. So, each customer ends up paying £9 plus the waiter keeps £2, making £29 in total. What happened to the missing £1?
If he'd kept all of the £5, you'd be saying each guy had paid £10, + £5 = £35.

Your maths is a nonsense.

Can it be milked?

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Re: Maths Question

Post by Rhys Benjamin » Wed Sep 29, 2010 3:35 pm

Grade 2:

NO CALCULATORS!

((6 x 6)) + 497 -( (log(log|3 x 6|(6 x 6))) / 6 ) / 5


HA HA HA HA HA !!!!!! :twisted: :twisted:

To make things easier, to the nearest one decimal place.

Corby, I did this in my head AND on a calculator and both equated to the same thing.


Matt, this isn't homework.

Who wants an F1 maths question?
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Re: Maths Question

Post by Ben Wilson » Wed Sep 29, 2010 4:06 pm

Rhys Benjamin wrote:Who wants an F1 maths question?
I think I can safely guess the answer to THAT one.

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Re: Maths Question

Post by Rhys Benjamin » Wed Sep 29, 2010 4:10 pm

Ben Wilson wrote:
Rhys Benjamin wrote:Who wants an F1 maths question?
I think I can safely guess the answer to THAT one.
So what's the answer?
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Re: Maths Question

Post by Rhys Benjamin » Wed Sep 29, 2010 5:12 pm

I'll give it anyway.

A car in qualifying trim can achieve a lap time of 1:20.450 at a particular circuit. At the start the qualifying lap it has 5kg of fuel. For every 10kg of fuel it carries, the lap time is increased by 0.35 seconds and for every lap the tyres cover, their performance degrades so that they are slower by 0.05 seconds every lap. For the race on this circuit, the car will consume an average of 2.25kg of fuel per lap and will start the race (lights out) with a fuel load of 153kg and on tyres that have covered 4 laps prior to race start.

QUESTION: What is the car's theoretical lap time on lap 10 of the race?

Edited following Matt's comments.

No Calculators.
Last edited by Rhys Benjamin on Wed Sep 29, 2010 5:41 pm, edited 1 time in total.
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Re: Maths Question

Post by Matt Morrison » Wed Sep 29, 2010 5:19 pm

That's a statement, not a question.

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Re: Maths Question

Post by Rhys Benjamin » Wed Sep 29, 2010 5:42 pm

Matt Morrison wrote:That's a statement, not a question.
Forgot to add the question. :oops:
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Re: Maths Question

Post by Charlie Reams » Wed Sep 29, 2010 6:00 pm

Rhys Benjamin wrote:I'll give it anyway.

A car in qualifying trim can achieve a lap time of 1:20.450 at a particular circuit. At the start the qualifying lap it has 5kg of fuel. For every 10kg of fuel it carries, the lap time is increased by 0.35 seconds and for every lap the tyres cover, their performance degrades so that they are slower by 0.05 seconds every lap. For the race on this circuit, the car will consume an average of 2.25kg of fuel per lap and will start the race (lights out) with a fuel load of 153kg and on tyres that have covered 4 laps prior to race start.

QUESTION: What is the car's theoretical lap time on lap 10 of the race?

Edited following Matt's comments.

No Calculators.
So the car consumes 2.25kg of fuel per lap no matter how long it takes or how much fuel it's carrying?

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Re: Maths Question

Post by Rhys Benjamin » Wed Sep 29, 2010 6:18 pm

Charlie Reams wrote:
Rhys Benjamin wrote:I'll give it anyway.

A car in qualifying trim can achieve a lap time of 1:20.450 at a particular circuit. At the start the qualifying lap it has 5kg of fuel. For every 10kg of fuel it carries, the lap time is increased by 0.35 seconds and for every lap the tyres cover, their performance degrades so that they are slower by 0.05 seconds every lap. For the race on this circuit, the car will consume an average of 2.25kg of fuel per lap and will start the race (lights out) with a fuel load of 153kg and on tyres that have covered 4 laps prior to race start.

QUESTION: What is the car's theoretical lap time on lap 10 of the race?

Edited following Matt's comments.

No Calculators.
So the car consumes 2.25kg of fuel per lap no matter how long it takes or how much fuel it's carrying?
Yup.
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Re: Maths Question

Post by Ian Volante » Wed Sep 29, 2010 6:40 pm

Rhys Benjamin wrote:
Charlie Reams wrote:
Rhys Benjamin wrote:I'll give it anyway.

A car in qualifying trim can achieve a lap time of 1:20.450 at a particular circuit. At the start the qualifying lap it has 5kg of fuel. For every 10kg of fuel it carries, the lap time is increased by 0.35 seconds and for every lap the tyres cover, their performance degrades so that they are slower by 0.05 seconds every lap. For the race on this circuit, the car will consume an average of 2.25kg of fuel per lap and will start the race (lights out) with a fuel load of 153kg and on tyres that have covered 4 laps prior to race start.

QUESTION: What is the car's theoretical lap time on lap 10 of the race?

Edited following Matt's comments.

No Calculators.
So the car consumes 2.25kg of fuel per lap no matter how long it takes or how much fuel it's carrying?
Yup.
This offends the rocket scientist in me.
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Re: Maths Question

Post by Kai Laddiman » Wed Sep 29, 2010 7:00 pm

Ian Volante wrote:This offends the rocket scientist in me.
What are you doing eating rocket scientists?
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Re: Maths Question

Post by Matt Morrison » Wed Sep 29, 2010 7:06 pm

Kai Laddiman wrote:
Ian Volante wrote:This offends the rocket scientist in me.
What are you doing eating rocket scientists?
How differently you'll tell that joke in butt a few years time, Kai...

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Re: Maths Question

Post by Rhys Benjamin » Wed Sep 29, 2010 7:07 pm

Kai Laddiman wrote:
Ian Volante wrote:This offends the rocket scientist in me.
What are you doing eating rocket scientists?
That's the first joke on this forum that has made me verbally laugh.
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Re: Maths Question

Post by Jon Corby » Wed Sep 29, 2010 7:12 pm

Rhys Benjamin wrote:
Kai Laddiman wrote:
Ian Volante wrote:This offends the rocket scientist in me.
What are you doing eating rocket scientists?
That's the first joke on this forum that has made me verbally laugh.
Verbally? You said "ha ha ha"?

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Re: Maths Question

Post by Rhys Benjamin » Wed Sep 29, 2010 7:23 pm

Jon Corby wrote:
Rhys Benjamin wrote:
Kai Laddiman wrote:
What are you doing eating rocket scientists?
That's the first joke on this forum that has made me verbally laugh.
Verbally? You said "ha ha ha"?
I sniggered.
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Re: Maths Question

Post by Gavin Chipper » Wed Sep 29, 2010 7:29 pm

Rhys Benjamin wrote:I'll give it anyway.

A car in qualifying trim can achieve a lap time of 1:20.450 at a particular circuit. At the start the qualifying lap it has 5kg of fuel. For every 10kg of fuel it carries, the lap time is increased by 0.35 seconds and for every lap the tyres cover, their performance degrades so that they are slower by 0.05 seconds every lap. For the race on this circuit, the car will consume an average of 2.25kg of fuel per lap and will start the race (lights out) with a fuel load of 153kg and on tyres that have covered 4 laps prior to race start.

QUESTION: What is the car's theoretical lap time on lap 10 of the race?

Edited following Matt's comments.

No Calculators.
It's not that exciting as far as questions go. How many laps had the tyres done prior to the qualifying lap? I'll assume they were new tyres so just the "out" lap (i.e. one). And at the start of lap 10 the tyres have done 4+9=13 so 12 more laps. 12*0.05=0.6. So that adds 0.6s to the lap time.

The car has 153-9*2.25kg of fuel so that's 153-20.25 = 132.75kg. That's 127.75kg more than for the qualifying lap. So that will make 127.75*0.35/10 seconds diffzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzz

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Re: Maths Question

Post by Rhys Benjamin » Wed Sep 29, 2010 7:30 pm

Gavin Chipper wrote:
Rhys Benjamin wrote:I'll give it anyway.

A car in qualifying trim can achieve a lap time of 1:20.450 at a particular circuit. At the start the qualifying lap it has 5kg of fuel. For every 10kg of fuel it carries, the lap time is increased by 0.35 seconds and for every lap the tyres cover, their performance degrades so that they are slower by 0.05 seconds every lap. For the race on this circuit, the car will consume an average of 2.25kg of fuel per lap and will start the race (lights out) with a fuel load of 153kg and on tyres that have covered 4 laps prior to race start.

QUESTION: What is the car's theoretical lap time on lap 10 of the race?

Edited following Matt's comments.

No Calculators.
It's not that exciting as far as questions go. How many laps had the tyres done prior to the qualifying lap? I'll assume they were new tyres so just the "out" lap (i.e. one). And at the start of lap 10 the tyres have done 4+9=13 so 12 more laps. 12*0.05=0.6. So that adds 0.6s to the lap time.

The car has 153-9*2.25kg of fuel so that's 153-20.25 = 132.75kg. That's 127.75kg more than for the qualifying lap. So that will make 127.75*0.35/10 seconds diffzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzz
But what's the lap time? No bullshit, just a number please.
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Re: Maths Question

Post by Gavin Chipper » Wed Sep 29, 2010 7:34 pm

Rhys Benjamin wrote:No bullshit, just a number please.
6

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Re: Maths Question

Post by Rhys Benjamin » Wed Sep 29, 2010 7:39 pm

Gavin Chipper wrote:
Rhys Benjamin wrote:No bullshit, just a number please.
6
All Right.

ANSWERS:(In seconds)The theoretical lap time would be 80.45 - (5 / 10 x 0.35). Starting lap 10, the car would have on board 153 - (9 x 2.25)kg of fuel = 132.75kg This would slow the car by 132.75 / 10 x 0.35 = 4.65 secs. The tyres by this stage would have covered 9 + 4 = 13 laps and would therefore have lost 13 x 0.05 secs = 0.65 secs of preformance. The theoretical lap time would therefore be 80.275 + 4.65 + 0.65 = 85.575 secs.

1:25.575

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