Apair of shoes is on sale for 30% off. the original price is p. which expression can be used to find the price of the shoes after the discount? 0.30p 0.70p 1.30p 30p

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?