Question

A carpenter has 28 nails from a previous job and needs to buy more. A store has 7 boxes of nails and each box contains 100 nails. The carpenter needs to buy at least 3 boxes. The number of nails the carpenter will have after purchasing n boxes is represented by a function.

f(n)=100n+28

What is the practical domain of the function?



Responses

a all integers from 3 to 7, inclusive
a all integers from 3 to 7, inclusive

b all real numbers
b all real numbers

c all real numbers from 3 to 7, inclusive
c all real numbers from 3 to 7, inclusive

d {328, 428, 528, 628, 728}

Answer 1

Answer: a. all integers from 3 to 7, inclusive.

Reason: n counts whole boxes, so n must be an integer; the carpenter must buy at least 3 boxes and the store has at most 7 boxes, so n ∈ {3,4,5,6,7}.