Sam bought brushes for $8, a palette for $5, and oil paints for $15. he paid $29.82 in all. what sale-tax rate did sam pay? 0.06%

Pls! does anybody know a shortcut for answering these types of questions in the future?

The probability that a college student belongs to a health club is 0.3. the probability that a college student lives off-campus is 0.4. the probability that a college student belongs to a health club and lives off-campus is 0.12. find the probability that a college student belongs to a health club or lives off-campus. tip: p(a or b) = p(a) + p(b) - p(a and b) 0.54 0.58 0.70 0.82

Aramp rises 4 feet over a distance of 10 feet. what is the length of the ramp?