Question

В ящике 15 изделий первого сорта 5- второго сорта и 15- третьего сорта. Найти вероятность того, что наугад взятое изделие- не третьего сорта. Плиз с подробным решением

Answer 1

Надо сосчитать сколько всего изделий
15+5+15=35 это всего изделий
Считаем изделия 1и2 сорта
15+5=20
Тогда получаем вероятность
20/35=0.57

Answer 2

Calculating the Probability of Selecting a Non-Third Grade Item

To calculate the probability of randomly selecting an item that is not of the third grade from the box, we can use the following formula:

Probability (P) = Number of non-third grade items / Total number of items

Given: - Number of first grade items = 15 - Number of second grade items = 5 - Number of third grade items = 15

We want to find the probability of selecting an item that is not of the third grade.

Calculation

The total number of items in the box is the sum of the items of all grades: Total number of items = Number of first grade items + Number of second grade items + Number of third grade items

Total number of items = 15 (first grade) + 5 (second grade) + 15 (third grade)

Total number of items = 35

The number of non-third grade items is the sum of the first and second grade items: Number of non-third grade items = Number of first grade items + Number of second grade items

Number of non-third grade items = 15 (first grade) + 5 (second grade)

Number of non-third grade items = 20

Now, we can calculate the probability: Probability (P) = Number of non-third grade items / Total number of items Probability (P) = 20 / 35 Probability (P) = 4 / 7

So, the probability of randomly selecting an item that is not of the third grade is 4/7.

Conclusion

The probability of selecting an item that is not of the third grade from the box is 4/7.