What is the lowest common multiple of 9, 12 , 15

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?

Isaac wants the equation below to have no solution when the missing number is placed in the box. which number should he place in the box?

Ben and cam are scuba diving. ben is 15.815.8 meters below the surface of the water. cam is 4.24.2 meters above ben. what is cam's position relative to the surface of the water? choose 1 choose 1 (choice a) a 11.611.6 meters above the surface of the water (choice b) b 11.611.6 meters below the surface of the water (choice c) c 2020 meters above the surface of the water (choice d) d 20 meters below the surface of the water