Seventy eight students are separated into groups of 8 for a field trip. how many groups are there? the remaining students form a smaller group of how many students?

Compare these two waves: the blue and orange waves have the same pitch, but the blue wave is louder. the blue and orange waves have the same volume, but the blue wave has a higher pitch. the orange wave has a higher pitch, but the blue wave is louder. the blue wave has a higher pitch, but the orange wave is louder.

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?

A50-foot ladder is leaning against a vertical wall. if the base of the ladder is 45 feet from the base of the wall, find the angle the bottling of the ladder makes with the ground.