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There are 10 stations on a railway line. The number of different journey tickets that are required by the authorities, is

Correct Answer: 90

Explanation:

There are 10 station on railway line.
So, the number of different journey tickets between two station from given 10 stations from one side = ¹⁰C₂ = 10 x 9/2 = 45.
Similarly, number of different journey tickets from other side = 45
∴ Total number of tickets to be generated by authorities. = 45 + 45 = 90

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