Lenny Conundrum #165

[burntouttrash]

Now why have I spent my two years of Maths A level learning how to differentiate exponentials and use correlation coefficients and calculate the resultant forces of vans crashing into one another but not how to do something like this?? Argh.

[N4p4]

i think there is a catch....
as i know 1m³ = 1000L is this right???
the volume of the sphere is in m³ and the answer is in L

[AySz88]

Now why have I spent my two years of Maths A level learning how to differentiate exponentials and use correlation coefficients and calculate the resultant forces of vans crashing into one another but not how to do something like this?? Argh.

It looks like you're almost there, since integration is the opposite of differentiation....

[farside]

Another significant figures guessing game, hoping you choose to use the same number of decimal places during the calculation as Neopets does. Annoying.

Ahhh, but that's why you memorize pi to 10 decimal places....

Well, that's one of the things. If I remember correctly, quite often in standardized tests, you're told what value to use for pi (how many decimal places). But that's not the only thing at issue here. As someone already mentioned (so I'm not ruining this puzzle), at some point, you have a conversion where you must move the decimal place around a few times to the right. That's when significant figures is important. It should be noted that all the figures given in the problem are single decimal. If you're doing calculations out to one decimal, you will end up with a different answer in the end versus two decimals, and two decimals versus three, etc. Try it and see. You just have to hope you're using the same number of decimal places as Neopets. This has happened in the Conundrums before.

By the way, you can do this with calculus, but it's not necessary to do so. There are equations available for calculating this sort of thing already without having to derive from scratch.

[AySz88]

Another significant figures guessing game, hoping you choose to use the same number of decimal places during the calculation as Neopets does. Annoying.

Ahhh, but that's why you memorize pi to 10 decimal places....

Well, that's one of the things. If I remember correctly, quite often in standardized tests, you're told what value to use for pi (how many decimal places). But that's not the only thing at issue here. As someone already mentioned (so I'm not ruining this puzzle), at some point, you have a conversion where you must move the decimal place around a few times to the right. That's when significant figures is important. It should be noted that all the figures given in the problem are single decimal. If you're doing calculations out to one decimal, you will end up with a different answer in the end versus two decimals, and two decimals versus three, etc. Try it and see. You just have to hope you're using the same number of decimal places as Neopets. This has happened in the Conundrums before.

I think the significant figure rules say that you don't round to significant figures until the final answer (at least that's what the AP rules are), and since it's "round up to nearest bucket" I don't think this is a sig fig problem anyway.... Unless you mean TNT messes up the sig fig rules?

[farside]

I think the significant figure rules say that you don't round to significant figures until the final answer (at least that's what the AP rules are), and since it's "round up to nearest bucket" I don't think this is a sig fig problem anyway.... Unless you mean TNT messes up the sig fig rules?

If that's the "AP rule", then I disagree with it. If I have a number that I know to be accurate only to 1/10th, such as 45.1, and I convert that, multiplying by say 1,000, I cannot then say my answer 45,100 is accurate to 1/10th (or write it as 45,100.0). It is only accurate to the 100ths place. Common sense, right?

Anyway, I'm not sure Neopets cares about any significant figures rules, which is why it can be hard to figure what they're expecting.

[AySz88]

I think the significant figure rules say that you don't round to significant figures until the final answer (at least that's what the AP rules are), and since it's "round up to nearest bucket" I don't think this is a sig fig problem anyway.... Unless you mean TNT messes up the sig fig rules?

If that's the "AP rule", then I disagree with it. If I have a number that I know to be accurate only to 1/10th, such as 45.1, and I convert that, multiplying by say 1,000, I cannot then say my answer 45,100 is accurate to 1/10th (or write it as 45,100.0). It is only accurate to the 100ths place. Common sense, right?

Anyway, I'm not sure Neopets cares about any significant figures rules, which is why it can be hard to figure what they're expecting.

No, that's not what I meant; the sig fig rules still apply but you don't round to sig figs at intermediate values. For example, if you do 13/99 = 0.13131313 and need to do additional math on that new value, you don't round to 0.13 first, you would do whatever math you need to first, then round to 2 sig figs (assuming nothing else changes it).

[poohroony]

i think there is a catch....
as i know 1m³ = 1000L is this right???
the volume of the sphere is in m³ and the answer is in L

Nope the answer is in bucketfuls As in "how many bucketfuls of water are required to fill the tank to the required depth?"

Can I check with someone? I only got my answer now, i'm too late for the prize but atleast i'll get some np

[N4p4]

i think there is a catch....
as i know 1m³ = 1000L is this right???
the volume of the sphere is in m³ and the answer is in L

Nope the answer is in bucketfuls As in "how many bucketfuls of water are required to fill the tank to the required depth?"

Can I check with someone? I only got my answer now, i'm too late for the prize but atleast i'll get some np

Yeah its in bucketfuls, but every bucketfuls, hold 10 L and the sphere R is 4,5 M so the volume of the sphere is in M³.
So the right answer is the volume of the liquid in M³ *1000 to transf. in L and /10 to transf. in bucketfuls.

Is this right???

Ty...

[poohroony]

Yup thats right, but I still need to check my answer with someone