Suppose a plumber charges $160 for the first hour plus $70 for each additional hour. Write an expression for the cost (in dollars) of a job lasting n hours.
A) $160 + 70 n$
B) $160 + 70 ( n - 1 )$
C) $160 \cdot 70 ^ { \mathrm { n } - 1 }$
D) $230 \mathrm { n }$

Question

Suppose a plumber charges $160 for the first hour plus $70 for each additional hour. Write an expression for the cost (in dollars) of a job lasting n hours. 
A) $160 + 70 n$
B) $160 + 70 ( n - 1 )$
C) $160 \cdot 70 ^ { \mathrm { n } - 1 }$
D) $230 \mathrm { n }$

Quizplus · Accepted Answer

The correct expression is $160 + 70 ( n - 1 )$, because the first hour costs $160 and each additional hour (n-1 hours) costs $70.

Suppose a Plumber Charges $160 for the First Hour Plus 160+70n160 + 70 n160+70n

Suppose a Plumber Charges $160 for the First Hour Plus $160 + 70 n$