Question

Cindy has 26 nickels. She is getting rolls of nickels from the bank. She has enough money to get up to 10 rolls of nickels and each roll contains 40 nickels. The bank will not give partial rolls. The function that models the number of nickels Cindy will have after leaving the bank is f(r)=40r+26, where r is the number of rolls of nickels she gets. What is the practical domain of the function?

A) all real numbers
B) r>1
C) {66, 106, 146, 186, 226, 266, 306, 346, 386, 426}
D) all integers from 1 to 10, inclusive

Answer 1

The answer is C I think 

Answer 2

Answer: Option D is the right answer. The practical domain of the function=all integers from 1 to 10, inclusive.

Explanation:

Given function f(r)=40r+26, where r is the number of rolls of nickels she gets.

as it is already mentioned that she can get up to 10 rolls of nickels.

Therefore domain of function contains r ≤10,such that r is a natural number.

i.e.Domain of f(r)=all integers from 1 to 10, inclusive.

Domain of a f(x) is a set of values of x which make function f(x) well defined.