Question

The cost to mail a package is $8 for the first 4 pounds and 25 cents for each additional ounce. Which of the following functions represents the cost to mail a package if x is the number of ounces over 4 pounds?

f( x) = 32 + 0.25 x
f( x) = 0.25( x + 4)
f( x) = 0.25+ 8 x
f( x) = 8 + 0.25 x

Answer 1

f(x) = 8 + 0.25x

Explanation:

The minimum cost is $8, for up to 4 pounds.

The added cost is ($0.25/oz)(x), where x is trhe ounces over 4 pounds

The total cost is the sum of these two:

f(x) = 8 + 0.25x