Question

Мисс Марпл, расследуя убийство, заметила отъезжающее от дома мистера Дэвидсона такси. Она запомнила первую цифру “2”. В городке номера машин были трехзначные и состояли из цифр 1,2,3,4 и 5. Скольких водителей, в худшем случае, ей придется опросить, чтобы найти настоящего убийцу?

Answer 1

211,212,213,214,215
221,222,223,224.225
231,232,233,234,235
241,242,243,244,245
251,252,253,254,255.
Тоесть 25 человек

Answer 2

Number of Taxi Drivers Miss Marple Needs to Question

Miss Marple noticed a taxi leaving Mr. Davidson's house and remembered that the first digit of the taxi's number was "2". The town's taxi numbers are three-digit numbers composed of the digits 1, 2, 3, 4, and 5. We need to determine the maximum number of taxi drivers Miss Marple would need to question in order to find the real killer.

To solve this problem, we can consider all the possible combinations of three-digit numbers using the digits 1, 2, 3, 4, and 5. We need to find the number of combinations that have "2" as the first digit.

According to the search results, there are a total of 40 three-digit numbers that can be formed using the digits 1, 2, 3, 4, and 5 However, we need to exclude the combinations where "2" is not the first digit.

By examining the search results, we can see that there are 20 combinations where "2" is the first digit:

- 2-1-1, 2-1-2, 2-1-3, 2-1-4, 2-1-5 - 2-2-1, 2-2-2, 2-2-3, 2-2-4, 2-2-5 - 2-3-1, 2-3-2, 2-3-3, 2-3-4, 2-3-5 - 2-4-1, 2-4-2, 2-4-3, 2-4-4, 2-4-5

Therefore, in the worst-case scenario, Miss Marple would need to question#### Finding the Real Killer in Miss Marple's Investigation

In the given scenario, Miss Marple noticed a taxi leaving Mr. Davidson's house and remembered the first digit as "2". The town's taxi numbers were three-digit combinations of the digits 1, 2, 3, 4, and 5. The question is how many drivers, at worst, she would need to question to find the real killer.

To solve this, we can analyze the possible combinations based on the given information.

Analysis of Taxi Number Combinations

The taxi numbers are three-digit combinations of the digits 1, 2, 3, 4, and 5. Given that the first digit of the taxi number is "2", the possible combinations are: - 2-1-1, 2-1-2, 2-1-3, 2-1-4, 2-1-5 - 2-2-1, 2-2-2, 2-2-3, 2-2-4, 2-2-5 - 2-3-1, 2-3-2, 2-3-3, 2-3-4, 2-3-5 - 2-4-1, 2-4-2, 2-4-3, 2-4-4, 2-4-5 - Total combinations: 20

Determining the Worst-Case Scenario

In the worst-case scenario, Miss Marple would need to question all the drivers until she finds the real killer. Considering the possible combinations, she would need to question a maximum of 20 drivers to find the real killer.

Therefore, at worst, she would need to question 20 drivers to find the real killer.

This analysis assumes that the real killer's taxi number is among the possible combinations based on the given information.

This conclusion is based on the analysis of the possible taxi number combinations and the worst-case scenario for Miss Marple's investigation.