In the domestic

In the domestic express train, there are 1st and 2nd class carriages. There are 2x more 2nd class carriages than 1st class. There are 10 compartments in each carriage. In 1st class, each compartment has 6 seats, and in 2nd class carriages, there are eight seats. There are a total of 440 seats in all the train compartments. How many carriages does 2nd class have, and how many seats does 1st class have?

Correct answer:

b =  4
x =  120

Step-by-step explanation:

$$\begin{gathered} b=2a \\ 10\cdot 6\cdot a+10\cdot 8\cdot b=440 \\ 10\cdot 6\cdot a+10\cdot 8\cdot 2\cdot a=440 \\ 220a=440 \\ a=\frac{440}{220}=2 \\ a=2 \\ b=2\cdot a=2\cdot 2=4 \end{gathered}$$

$x=10\cdot 6\cdot a=10\cdot 6\cdot 2=120$

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