2*x :5 *y

3: < >

< > = (3

*5*y) / 2*x

so how do I know from what is written in <> the amount of sugar for making amount of cake 3?! thanks beforehand

- Thread starter Ryan$
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2*x :5 *y

3: < >

< > = (3

so how do I know from what is written in <> the amount of sugar for making amount of cake 3?! thanks beforehand

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I think it's better to say "to" instead of "vs".… [ratio] 2:5 [describes] amount of cake vs amount of sugar …

2:5 denotes the ratio 2 parts cake to 5 parts sugar

You don't need symbol x for the amount of cake because you already said it's 3.… how much [sugar is needed if] amount of cake is 3 …

… [let's] assume x is the amount of cake …

You can find the sugar amount by solving a simple proportion.

\(\displaystyle \dfrac{2}{5} = \dfrac{3}{?}\)

Multiply on the diagonal and then divide by the number not used.

5 × 3 ÷ 2 = 7.5

You need 7.5 parts sugar for every 3 parts cake.

Check:

2/5 = 0.4

3/7.5 = 0.4

In other words, 2/5 = 3/7.5

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