what is the charge per minute for the minutes over 350 per month?

Question

Noslo also has cell phone service from Varisoon Wireless. She pays a flat fee of $30.95 for 350 minutes per month. Any minutes over 350 are at an additional cost. In November, Noslo's bill for wireless service was $108.70 for 475 minutes.

Answer 1

line 1...kost=108.70$ for 475 minuts

line 2...base kost=30.95$ for 350 minuts

subtrakt line 2 from line 1...77.75 $ for 125 minuts

=0.622 $/minut over

Note base kost=30.95/350=0.0884 $/minut