Question

1. У Дарьи есть десять пятирублёвых монет. а) Сколькими способами (все монеты разные) Даша может заплатить за мороженое в магазине. Если мороженое стоит 10 рублей. б) Тот же вопрос. Но только Даше захотелось более вкусное мороженое, и оно стоит 15 рублей.2) У Василия есть пять двухрублёвых монет и семь пятирублевых. Вася хочет купить "Чупа-Чупс".а) Сколькими способами он оплатит свою покупку, если "Чупа-ПЛИИИЗ​

Answer 1

Ответ:

Пошаговое объяснение:

а) 10:5=2 монеты по пять рублей

б) 15:5=3 монеты по 5 рублей

2 ) сколько стоит чупа-чупс

пять двухрублевых монет составляют 10 рублей и 7 пятирублевых монет составляют 35 рублей.

Если сумма кратна 5 или десяти в пределах 45 рублей можно оплатить :

пятью двухрублевыми и остальное 5-рублевыми

если сумма некратна 5 и десяти , и нечетная,то:

11 руб.= 5*1+2*3

12руб.=5*2+2*1

13руб=5*1+2*4

19=5*3+2*2

21= 5*3+2*3

23=5*3+2*4

27=5*5+2

29=5*5+2*2

31=5*5+2*3

33=5*5+2*4

37=5*7+2

39=5*7+2*2

41=5*7+2*3

43=5*7+2*4

Answer 2

1. а) To calculate the number of ways Dasha can pay for the ice cream with her ten five-ruble coins, we need to find the number of combinations. Since all the coins are different, we can use the formula for combinations without repetition. The formula is:

nCr = n! / (r!(n-r)!)

Where n is the total number of items (coins) and r is the number of items (coins) we want to select.

In this case, Dasha has 10 five-ruble coins, and she wants to pay 10 rubles for the ice cream. So, we need to find the number of ways she can select 10 coins out of 10. Plugging the values into the formula, we get:

10C10 = 10! / (10!(10-10)!) = 1

Therefore, Dasha can pay for the ice cream in only one way if the ice cream costs 10 rubles. [[1]]

б) If Dasha wants to buy a more expensive ice cream that costs 15 rubles, the calculation is slightly different. Now, she needs to select 15 rubles worth of coins from her collection of ten five-ruble coins.

Using the same formula, we can calculate the number of ways she can select the coins:

10C15 = 10! / (15!(10-15)!) = 0

Since Dasha only has ten five-ruble coins, which amounts to a total of 50 rubles, she cannot pay for an ice cream that costs 15 rubles. Therefore, there are zero ways for her to pay for the more expensive ice cream. [[1]]

2. а) To calculate the number of ways Vasily can pay for his "Chupa-Chups" with his five two-ruble coins and seven five-ruble coins, we can use the same formula for combinations without repetition.

Vasily has a total of 5 two-ruble coins and 7 five-ruble coins. Let's assume the "Chupa-Chups" costs X rubles. We need to find the number of ways he can select coins that add up to X rubles.

For example, if the "Chupa-Chups" costs 10 rubles, we need to find the number of ways he can select coins that add up to 10 rubles.

Using the formula, we can calculate the number of ways:

(5+7)C10 = 12! / (10!(12-10)!) = 66

Therefore, Vasily can pay for his "Chupa-Chups" in 66 different ways if it costs 10 rubles. [[2]]

б) If the "Chupa-Chups" costs a different amount, we can calculate the number of ways using the same formula. For example, if the "Chupa-Chups" costs 15 rubles:

(5+7)C15 = 12! / (15!(12-15)!) = 0

Since Vasily only has a total of 50 rubles (5*2 + 7*5), he cannot pay for a "Chupa-Chups" that costs 15 rubles. Therefore, there are zero ways for him to pay for the more expensive "Chupa-Chups". [[2]]

Please let me know if there's anything else I can help you with!