In the domestic

In a domestic express train, there are 1st and 2nd class carriages. There are twice as many 2nd class carriages as 1st class carriages. Each carriage has 10 compartments. Each 1st class compartment has 6 seats, and each 2nd class compartment has 8 seats. There are 440 seats in total. How many 2nd class carriages are there, and how many seats does the 1st class have in total?

Final 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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