# Pcr

Im looking at Dec 07 PCR
When doing the material required for production for the 250ml carton and the 500 ml carton, am i dividing the production in ml by the units per square metre needed.
In other questions however i multiply the production by the amount of material needed per unit?!

Im abit confused about why i am dividing!?!

gahh i think this is probably a really silly question but im sure someone will point itout!!!!

thankyouuu!

• GemmaLouise
If you normally mutiply the centremetres per unit by the number of units, why not do the same in this question?

You need to produce 252,000 250ml cartons, so at 40sq cm per unit you'll need 10,100,000 sq cm.
You need to produce 101,000 500ml cartons, so at 50sq cm per unit you'll need 5,050,000 sq cm

Add it up and the total requirement is 15,150,000 sq cm
As there are 10,000 sq cms per sq metre this is 1,150 sq ms.
As the material is bought in sheets, some of each sheet is wasted - 2%
The good material (1,150 sq m) is 98% of the sheets bought

So when we adjust for wastage 1,546 sq metres are needed
(1,515 sq m of useful, 31 sq m wasted)
Sandy
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www.sandyhood.com