Question

Ученик наугад называет число от 21 до 30. Какова вероятность того, что названное число делится на 3, но не делится на 5? Срочно!!

Answer 1

Ответ:

Вероятность 0,3

Объяснение:

Всего 10 чисел

На 3 делятся: 21,24,27,30 их 4 числа

30 делится на 5

Вероятность 3/10=0,3

Answer 2

Probability of randomly selecting a number between 21 and 30 that is divisible by 3 but not divisible by 5

To calculate the probability of randomly selecting a number between 21 and 30 that is divisible by 3 but not divisible by 5, we need to determine the total number of numbers in the given range that satisfy these conditions and divide it by the total number of numbers in the range.

The numbers between 21 and 30 are: 21, 22, 23, 24, 25, 26, 27, 28, 29, and 30.

Out of these numbers, the ones that are divisible by 3 but not divisible by 5 are: 21, 24, 27, and 30.

Therefore, there are 4 numbers that satisfy the given conditions.

The total number of numbers in the range is 10.

To calculate the probability, we divide the number of favorable outcomes (4) by the total number of outcomes (10):

Probability = Number of favorable outcomes / Total number of outcomes = 4/10 = 2/5 = 0.4 = 40%

So, the probability of randomly selecting a number between 21 and 30 that is divisible by 3 but not divisible by 5 is 40%.