Answer:
product
Step-by-step explanation:
A)
First note that the plates can have between 4 and 6 symbols so we will need to find the number of plates with 4 symbols, 5 symbols and 6 symbols. We add these to get the total. In this part repetition of symbols is allowed. Since there are 26 + 10 =36 possible symbols we look at each position on the plate and think of how many choices there are. We multiply the number f choices using the counting principal since the choices are each independent -- one symbol does not affect another. There are 36 choices for the first symbol, 35 for the second and so on. The number of plates is:
4-symbols = (36)(36)(36)(36)=36^4
5 symbols = (36)^5
6 symbols = 36^6
So the total here is: 36^4+36^5+36^6
B) Here we do not repeat symbols so there are 36 choices for the first symbol but only 35 for the next and 34 for the one after and so on.
4-symbols = (36)(35)(34)(33)
5 symbols = (36)(35)(34)(33)(32)
6 symbols = (36)(35)(34)(33)(32)(31)
So the total here is: (36)(35)(34)(33)+(36)(35)(34)(33)(32)+(36)(35)(34)(33)(32)(31)
c)
In order for there to be a repeated symbol we have 36 choices for the first symbol, 36 for the next and so on. However, for the last symbol we have to pick from one of the ones already selected so there are 3, 4 or 5 choices respectively.
4-symbols = (36)(36)(36)(3)
5 symbols = (36)(36)(36)(36)(4)
6 symbols = (36)(36)(36)(36)(36)(5)
So the total here is: (36^3)(3)+(36^4)(4)+(36^5)(5)
D)
The probability is given by (the number of plates with at least one repeated symbol)/(the total number of plates if repetitions are allowed) = (the answer to c) / (the answer to a)
Answer:
Step-by-step explanation:
Let x represent the number of stamps from Europe.
Let y represent the number of stamps from Africa.
Let z represent the number of stamps from Asia.
She has 47 stamps in all. This means that
x + y + z = 47 - - - - - - - - - - - 1
The number of African stamps is 2 times the number of Asian stamps. This means that
y = 2z
She has 20 stamps from Europe. Therefore, substituting x = 20 and y = 2z into equation 1, it becomes
20 + 2z + z = 47
3z = 47 - 20 = 27
z = 27/3 = 9
y = 2z = 2 × 9
y = 18
She has 20 stamps from Europe, 18 stamps from Africa and 9 stamps Asia.
No, not all of these questions are statistical.
The first question does Mary like snacks is a Yes or No question which doesn't provide any statistics.
