ALGEBRA
posted by CHANTELL .
Company A charges $55 per day plus $0.35 per mile to rent a car. Company B charges $50 per day plus $0.40 per mile. Jack wants to rent a car for three days. How many miles should Jack be traveling so that Company A is less expensive than Company B?

The volume of a rectangular slab of concrete needs to exceed 72 cu. ft. If the length is 12 feet and the width is 8 feet, how thick does the concrete slab need to be?

“Collin left the party one half hour before Gabriel. Terrence left an hour and a half later than Gabriel. Together the three of them stayed more than four hours. How long did they each stay at the party?”

Laura found $2.15 in quarters and nickels in the bottom of her purse. There were seven fewer quarters than nickels. How many nickels and quarters did she find?

company A:
cost = .35m + 55
company B:
cost = .4m + 50
solve
.4m+50 = .35m+55
.05m = 5
m = 5/.05 = .....
Please do not post a new problem as an appendix to a previous post.
Tutors will think it has been answered and might ignore the entire post
second Problem:
let the thickness be x ft
so 12(8)x ≥ 72
x ≥ 72/96
x ≥ 3/4 ft 
You are more likely to get each answered if you post each question as an individual posting