c4countdown

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?

Inflation.

Do your own homework.

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.

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)".

Oh, this isn't homework, something I saw in a book.

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.

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?

Grade 2:

NO CALCULATORS!

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


HA HA HA HA HA !!!!!!

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?

Rhys Benjamin wrote:Who wants an F1 maths question?

I think I can safely guess the answer to THAT one.

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?

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.

That's a statement, not a question.

Matt Morrison wrote:That's a statement, not a question.

Forgot to add the question.

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?

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.

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.

Ian Volante wrote:This offends the rocket scientist in me.

What are you doing eating rocket scientists?

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...

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.

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"?

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.

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

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.

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

6

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