Ashley recently opened a store that uses only natural ingredients. she wants to advertise her products by distributing bags of samples in her neighborhood. it takes ashley \dfrac{2}{3} 3 2 start fraction, 2, divided by, 3, end fraction of a minute to prepare one bag. it takes each of her friends 75\%75%75, percent longer to prepare a bag.

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?