Answer:
y = 20 + .5x
Step-by-step explanation:
Suppose that a cell phone monthly rate plan costs the user 5 cents per minute beyond a fixed monthly fee of $20. This implies that the relationship between monthly cost and monthly number of minutes is linear. Write an equation that relates total monthly cost to monthly minutes used.
Fixed monthly fee = $20
Fee per minute = $0.5
Number of minutes = x
Variable monthly cost = 0.5x
Let Total monthly cost = y
Total monthly cost = fixed monthly cost + variable monthly cost
y = 20 + .5x
Equation that relates total monthly cost to monthly minutes used is y = 20 + .5x
Answer:
Assign a number to each student, and use a computer program to generate 100 random numbers between 1 and 2000. Ask those students whose numbers are selected.
Step-by-step explanation:
Answer:
The probability is 
Step-by-step explanation:
We can divide the amount of favourable cases by the total amount of cases.
The total amount of cases is the total amount of ways to put 8 rooks on a chessboard. Since a chessboard has 64 squares, this number is the combinatorial number of 64 with 8,
For a favourable case, you need one rook on each column, and for each column the correspondent rook should be in a diferent row than the rest of the rooks. A favourable case can be represented by a bijective function
with A = {1,2,3,4,5,6,7,8}. f(i) = j represents that the rook located in the column i is located in the row j.
Thus, the total of favourable cases is equal to the total amount of bijective functions between a set of 8 elements. This amount is 8!, because we have 8 possibilities for the first column, 7 for the second one, 6 on the third one, and so on.
We can conclude that the probability for 8 rooks not being able to capture themselves is

Answer:
The answer is C.-216
Step-by-step explanation: