Maths Problem

Mark has a clay model.
He will now make a clay statue that is mathematically similar to the clay model.
The model has a base area of 6cm squared
The statue will have a base area of 253.5 squared
Mark used 2kg of clay to make the model
Clay is sold in 10kg bags
Mark has to buy all the clay he needs to make the statue
How many bags of clay will Mark need to buy?

Reply 1

Neilly98

First you need to determine the scale factor. This is the number that the model has been scaled up by to make the statue.
To do this, divide 253.5 by 6 to get 42.3. This means the statue is 42.3 times bigger than the original model.

Now to find out how much clay is needed, you multiply the original quantity by your scale factor.
So if he used 2kg to make the original model, he uses 84.6kg (2 x 42.3) to make his statue.

Then simply divide 84.7 by 10 to find how many bags he needs. 84.7/10 = 8.47 bags.
Obviously he can't buy 0.47 bags, so you have to round to find the final amount needed. A common mistake would be to round down and say he needs 8 bags, but this won't be enough as he needs 84.7kg and 8 bags will only provide him with 80kg.

Therefore he needs 9 bags of clay.
Hope this helped, if you have questions, just ask! :smile:

Reply 2

Tutortutor

4

This question is to do with transitioning between the related ratios of LENGTH : AREA : VOLUME

The respective ratio of base area of clay model and statue is 6: 253.5 or 1: 169/4 (this fraction is important if this is on a NON CALC PAPER)

You then want to get to a ratio for Volume. But to do this you MUST FIRST take it back to a ratio for length.
IF you want to transition between Volume and Area you must go via Length first. ( Think of Length as your Home or base that you return to after a trip before going out to see someone else)

So to get from AREA to LENGTH you Square ROOT. So we get for L 1: 13/2 = 1: 6.5

To then get to Volume we must CUBE So we get for V 1: 2197/8 = 274.625

Now as M is prop to Volume for a constant density, when
we talk about Mass we USE the Volume ratio So 1kg of clay model = 274.625 kg statue
Meaning 2 kg = 549.25kg

As 1 bag = 10kg Mark would need 549.25/10 = 54.925 bags
Which means he would need to BUY 55 bags

(edited 6 years ago)

Reply 3

LoOK_WhO'sTalkiN

3

@Neilly98 COMPLETELY WRONG!!! I hope you're just someone who doesn't know maths and is failing to be helpful. If you are tricking people on purpose then you're just evil.

Reply 4

Haquer

3

Original post by Neilly98

First you need to determine the scale factor. This is the number that the model has been scaled up by to make the statue.
To do this, divide 253.5 by 6 to get 42.3. This means the statue is 42.3 times bigger than the original model.

Now to find out how much clay is needed, you multiply the original quantity by your scale factor.
So if he used 2kg to make the original model, he uses 84.6kg (2 x 42.3) to make his statue.

Then simply divide 84.7 by 10 to find how many bags he needs. 84.7/10 = 8.47 bags.
Obviously he can't buy 0.47 bags, so you have to round to find the final amount needed. A common mistake would be to round down and say he needs 8 bags, but this won't be enough as he needs 84.7kg and 8 bags will only provide him with 80kg.

Therefore he needs 9 bags of clay.
Hope this helped, if you have questions, just ask! :smile:

There are just so many mistakes to this. I don't know what this person is trying to do here. Please don't waste our time by commenting complete rubbish like this.

=GO SOMEWHERE ELSE THIS IS A WEBSITE FOR EDUCATION=