>>> A building has 10 floors. At the ground floor, 7 people enter the elevator. At the second floor, 3 people get off and 2 people enter. At the fourth floor, 5 people get off and 2 people enter. At the seventh floor, 1 person gets off and 3 people enter. Finally, at the tenth floor, everyone remaining in the elevator gets off. The question is, How many people were in the elevator when it started its journey, and how many total people exited the elevator by the end of its journey?

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The elevator started its journey with 7 people. Following the instructions, we can keep track of the number of people entering and exiting each floor. By the tenth floor, 7 (initial) - 3 (floor 2) + 2 (floor 4) - 5 (floor 7) + 2 (floor 10) = 3 people remain in the elevator. Therefore, the final number of people in the elevator is 3.

As for the total number of people who exited the elevator, we can calculate this by adding the initial number of people to the net change in the number of people in the elevator throughout its journey: 7 (initial) + (7 - 3 + 2 - 5 + 2) = 13 people.

In summary, there were 3 people in the elevator when it reached the tenth floor, and a total of 13 people exited the elevator during its journey.