Question

Школьник попросил троих друзей отгадать, какое он задумал число из набора: положительное, отрицательное, четное, нечетное, целое и дробное. Первый сказал, что если число четное, то оно положительное Второй предположил, что задуманное число четное или целое и положительное Третий был уверен, что если это число положительное, то оно нечетное Все три оказались правы. Какое число загадал школьник?

Answer 1

Это скорее всего 3 так как все вроде попадает по описание

Answer 2

Problem Analysis

The schoolboy asked three friends to guess the number he had in mind from a set of criteria: positive, negative, even, odd, whole, and fractional. The first friend said that if the number is even, then it's positive. The second friend suggested that the number is either even or whole and positive. The third friend was confident that if the number is positive, then it's odd. All three friends turned out to be correct. We need to determine the number the schoolboy had in mind.

Solution

Let's analyze the clues provided by the friends to deduce the characteristics of the number.

1. The first friend said that if the number is even, then it's positive. 2. The second friend suggested that the number is either even or whole and positive. 3. The third friend was confident that if the number is positive, then it's odd.

Deduction

From the first friend's statement, we know that the number is even and positive. From the second friend's statement, we know that the number is even or whole and positive. From the third friend's statement, we know that the number is positive and odd.

Conclusion

The only number that satisfies all these conditions is 1. It is the only positive, even, whole, and odd number.

Therefore, the number the schoolboy had in mind is 1.