Linnaeus 82847

The cook bought 54 desserts for each of the diners and paid 14.35 Euros for them. Creams were 0.30 Euro each, and Linnaeus cakes were 0.25 Euro each. How many creams and how many Linnaeus cakes did she buy?

Correct answer:

a =  17
b =  37

Step-by-step explanation:

$$\begin{gathered} a+b=54 \\ 0.30a+0.25b=14.35 \\ a+b=54 \\ 0.30\cdot a+0.25\cdot b=14.35 \\ a+b=54 \\ 0.3a+0.25b=14.35 \\ Row2-0.3\cdot Row1\to Row2 \\ a+b=54 \\ -0.05b=-1.85 \\ b=\frac{-1.85}{-0.05}=37 \\ a=54-b=54-37=17 \\ a=17 \\ b=37 \end{gathered}$$

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