Answer :

200g / 8= 25 (to find out how many grammes are needed for 1 cake...)
25 * 3 = 75 (to find out how many grammes are needed for 3 cakes...)
75 grammes of fat are needed to make 3 cakes!
Hope this helps...! :)
C=Cake(s)
G=Gram(s)

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8C=200G

Therefore:

C=200G/8

C=25G

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If C=25G,

3C=75G

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So 75g of fat will be used to make 3 cakes.