Question

На та­рел­ке лежат оди­на­ко­вые на вид пи­рож­ки: 4 с мясом, 5 с рисом и 21 с повидлом. Андрей на­у­гад вы­би­ра­ет один пи­ро­жок. Най­ди­те ве­ро­ят­ность того, что он ока­жет­ся с повидлом.

Answer 1

100 %-30
         x-21
x=21*100:30
x=70=7%
Ответ 7%или 70%

Answer 2

Вероятность-дробь
Числитель-число пирожков с повидлом
Знаменатель-число всех пирожков
21/30=7/10=70%

Answer 3

Problem Analysis

Andrey is choosing a random pastry from a plate that contains 4 meat pastries, 5 rice pastries, and 21 jam pastries. We need to find the probability that he chooses a jam pastry.

Solution

To find the probability, we need to calculate the ratio of the number of jam pastries to the total number of pastries on the plate.

The total number of pastries on the plate is the sum of the number of meat, rice, and jam pastries:

Total number of pastries = 4 (meat pastries) + 5 (rice pastries) + 21 (jam pastries)

Now, we can calculate the probability:

Probability of choosing a jam pastry = Number of jam pastries / Total number of pastries

Let's calculate the probability using the given information:

Total number of pastries = 4 + 5 + 21 = 30

Probability of choosing a jam pastry = 21 / 30

Calculation

The probability of Andrey choosing a jam pastry is 21/30.

Please let me know if I can help you with anything else.