Mr. williams is painting only the back of his barn. a gallon of paint covers 70 square feet. how many square feet will mr. williams be painting? how many gallons of paint does he need to buy? a) 264 ft2; 4 gallons b) 264 ft2; 3 gallons c) 276 ft2; 4 gallons d) 276 ft2; 3 gallons

How many different three-digit numbers can be formed using the digits 1 comma 2 comma 9 comma 6 comma 4 comma 3 comma and 8 without repetition? for example, 664 is not allowed.

True or false: the graph of y=f(bx) is a horizontal compression of the graph y=f(x) if b< 1

Each person in an it department of 25 people works on at least one of 3 major projects: system security, program implementation, platform development. 10 people work on system security, 13 work on program implementation, and 12 work on platform development. 4 people work on system security and platform development, 5 people work on program implementation and platform development, and 2 people work on all three projects. how many people work on system security and program implementation?