Work the following financial transactions. your station charges $15.95 for an oil change. as a promotion you sell six coupons for oil changes for $80. what percentage discount are you offering for customers who purchase the 6-coupon book? discount (to the nearest tenth) =

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?