Question

В денежной лотерее разыгрывается 30% выигрышей по 3 руб., 25% - по 5 руб., 40% - по 10 руб. и 5% - по 15 руб. Какова вероятность по двум билетам выиграть 20 руб.?

Answer 1

80% это 10р и 10р
или
30% это 15р и 5р

Answer 2

Calculating the Probability of Winning 20 Rubles with Two Tickets

To calculate the probability of winning 20 rubles with two tickets in the given lottery, we can use the concept of combinations and the formula for calculating the probability of an event.

The probability of winning a specific amount with one ticket can be calculated using the formula: $$ P(A) = \frac{m}{n} = \frac{C_{k}^{n}}{C_{N}^{n}} $$

Where: - $ N $ is the total number of tickets sold - $ k $ is the number of tickets that win a specific amount - $ n $ is the number of tickets drawn - $ m $ is the number of ways to choose $ k $ winning tickets out of $ N $ total tickets

Using the provided percentages for each winning amount, we can calculate the probability of winning each amount with one ticket.

1. Probability of Winning 3 Rubles: - Percentage: 30% - Calculation: $ P(3) = \frac{C_{3}^{100}}{C_{3}^{100}} = 0.941 $.

2. Probability of Winning 5 Rubles: - Percentage: 25% - Calculation: $ P(5) = \frac{C_{4}^{2} \cdot C_{4}^{3}}{C_{8}^{5}} = 0.429 $.

3. Probability of Winning 10 Rubles: - Percentage: 40% - Calculation: Not provided in the search results.

4. Probability of Winning 15 Rubles: - Percentage: 5% - Calculation: Not provided in the search results.

To calculate the probability of winning 20 rubles with two tickets, we need the probabilities for winning 10 and 15 rubles. Unfortunately, these probabilities are not provided in the search results.

Without the probabilities for winning 10 and 15 rubles, it's not possible to accurately calculate the probability of winning 20 rubles with two tickets. Additional information or calculations are needed to determine the probability of winning 20 rubles with two tickets in this lottery.