If on a scale drawing 15 feet are represented by 10 inches, then a scaleof 1/20 inch represents how many feet?

Ihave a 69 and an 82. the 69 is worth 40% of my grade and the 82 is worth 15%. can someone tell me my current average grade.

Pam buys a sleeve of ball bearings for her skateboard. each of the bearings is 1 1/5 inches wide. the sleeve is 9 3/5 inches long. how many ball bearings are in the sleeve? show your work.

Ab and bc form a right angle at point b. if a= (-3,-1) and b= (4,4) what is the equation of bc?