Problema Solution
Sullen subscribes to an online computer service that charges $9.50 per month for 30 hours online and $1.50 for each hour online in excess of 30 hours. Last month her bill was $20. How many extra hours was she charged?
Answer provided by our tutors
let us assume total hours in excess of 30 hours be x.
so, 9.5 + 1.5 * x = 20
x = 10.5/1.5 = 7 hours