Fabric cost calculation

Mom bought the boys the same fabric for their clothes. Joey has 2.5 m of fabric, Karl 1.25 m, and Luis 0.3 m more than Karl. How many crowns will they pay for fabric if 10 cm costs CZK 13.80?

Final Answer:

x =  648.6

Step-by-step explanation:

$$\begin{gathered} a=2.5\text{m}\to \text{cm}=2.5\cdot 100\text{cm}=250\text{cm} \\ b=1.25\text{m}\to \text{cm}=1.25\cdot 100\text{cm}=125\text{cm} \\ {c}_1=0.30\text{m}\to \text{cm}=0.30\cdot 100\text{cm}=30\text{cm} \\ c=b-c_1=125-30=95\text{cm} \\ {x}_1=13.80/10=\frac{69}{50}=1\frac{19}{50}=1.38\text{Kc/cm} \\ x=x_1\cdot (a+b+c)=1.38\cdot (250+125+95)=648.6 \end{gathered}$$

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