Question

John has 7 stamps. It takes one stamp to mail a letter. The number of letters he can mail, y, is a function of x, the number of stamps he has. Which answer choice best describes the domain of the function?

A. {1,2,3,4,5,6,7}
B. x≤ 7
C. 0≤ x≤ 7
D. {0,1,2,3,4,5,6,7}

Answer 1

The domain of the function representing the number of letters John can mail with the stamps he has is {0,1,2,3,4,5,6,7}, as it includes sending zero to seven letters using the stamps available to him.

Step-by-step explanation:

The question asks about the domain of a function that represents the number of letters John can mail with the stamps he has. The function is defined as the number of letters y that can be mailed as a function of x, the number of stamps John has. Given that John has 7 stamps and it takes one stamp to mail one letter, the domain of the function is the set of all possible values of x that John could use to mail letters. This means that the domain includes zero (since he could choose to send no letters) up to the number of stamps he has, which is 7.

Therefore, the correct description of the domain of the function is {0,1,2,3,4,5,6,7}, as this includes the possibility of sending zero letters (using no stamps) up to sending 7 letters (using all the stamps he has). The domain of this function cannot be negative, and it cannot exceed the number of stamps John has.