Problema Solution

math problem The phone company calculates a customer’s monthly cell phone bill as follows: monthly service charge: $35 voice charges: First 100 minutes: $0.018 per minute Second 100 minutes: $0.034 per minute Additional minutes: $0.055 per minute

a. What is the charge for a month in which 158 minutes were used?

b. What is the charge for a month in which 311 minutes were used?

c. Construct a piecewise function that gives the monthly charge for x minutes of usage.

Answer provided by our tutors

a.

35 + 0.018*100 + 0.034*(158 - 100) = $38.77

b.

35 + 0.018*100 + 0.034*100 + 0.055*(311 - 200) = $6.31

c.

f(x) = 35 + 0.018x, for x<=100

f(x) = 35 + 0.018*100 + 0.034(x - 100), for 100<x<=200

f(x) = 35 + 0.018*100 + 0.034*100 + 0.055(x - 200), for x > 200