Question doesn't make sense

[mathlover583]

Hi, is it just me or does this question not make sense? Is anyone able to do this and show me how to do this? A friend of mine has been sent this question but they haven't even been shown how to do something like this and they can't work out how they're meant to convert cm cubed to cm squared. They were able to work out the area of the curved rectangle to make 1856.0226cm2 and they then multiplied this by 525 to get 974411.86 cm2 total area to be painted on the 525 vases, but where do they go from there? I said I'd help but it seems like there's an error in the question to me. Thanks.

A company makes 600 cylindrical vases. 12.5% of vases are discarded due to faults. The sides of the remaining vases will be painted either blue or white. They have
800 000cm³ of blue paint and will use all of this up before painting the rest of the vases with white paint. If each cylindrical vase is 32.3cm high and 18.3cm diameter, what is the probability that a vase picked at random will be blue? Give your answer as a decimal.

 

[Deleted member 4993]

Hi, is it just me or does this question not make sense? Is anyone able to do this and show me how to do this? A friend of mine has been sent this question but they haven't even been shown how to do something like this and they can't work out how they're meant to convert cm cubed to cm squared. They were able to work out the area of the curved rectangle to make 1856.0226cm2 and they then multiplied this by 525 to get 974411.86 cm2 total area to be painted on the 525 vases, but where do they go from there? I said I'd help but it seems like there's an error in the question to me. Thanks.

A company makes 600 cylindrical vases. 12.5% of vases are discarded due to faults. The sides of the remaining vases will be painted either blue or white. They have
800 000cm³ of blue paint and will use all of this up before painting the rest of the vases with white paint. If each cylindrical vase is 32.3cm high and 18.3cm diameter, what is the probability that a vase picked at random will be blue? Give your answer as a decimal.

Somewhere "they" could have specified the thickness of the "painted layer". Please ask your friend to look for that detail.

May be Google can give you some estimate.

 

[mathlover583]

Hi, thanks for the reply - no the only information given was the information shown. It was that text precisely, with a diagram of the vase being 32.3cm by 18.3 cm. So this is what I thought, without the thickness of the painted layer of the vase you can't convert cm3 to cm2 can you?

 

[Dr.Peterson]

Hi, thanks for the reply - no the only information given was the information shown. It was that text precisely, with a diagram of the vase being 32.3cm by 18.3 cm. So this is what I thought, without the thickness of the painted layer of the vase you can't convert cm3 to cm2 can you?

Can you show us an image of the actual problem, so we can see if there is some hidden information? You might also check instructions elsewhere on the page, in case it says, say, "In all problems, assume paint is 1 mm thick," or something like that!

You're right that you need either information about the paint thickness, or direct information about the area some amount of paint can cover. Otherwise, you can't "convert" volume to area, because they aren't the same kind of quantity.

 

[mathlover583]

Hi, I wrote the problem word for word, the only thing I did do, because I couldn't insert the diagram of the cylinder, was I wrote 'If each cylindrical vase is 32.3cm high and 18.3cm diameter' rather than insert the diagram which showed you a cylinder with those dimensions. But other than this, word for word, nothing missing. So this is why my friend was unable to answer the question, and why I was scratching my head looking at it!
Thanks.