12. The charges for an international
Phone Company
Charges
call made using the calling card
for two phone companies are
Company A 350 plus 30 per minute
shown in the table.
Company B 450 plus 20 per minute
a. What is the length of a phone call that would cost the same no matter
which company is used?
10 minutes
b. Analyze Relationships When is it better to use the card from
Company B?