An educational researcher is studying two similar high schools in different states. Suppose that 50% of all 425 students at high school A have taken a college-level course, while 40% of all 525 students from high school B
have taken such a course. The researcher plans on taking separate random samples of 50 students from each
high school to look at the difference (A - B) between the proportions of students who have taken a college-
level course in each sample.

Jim is painting the inside of a circular helicopter pad. how many cans of paint would he need if the pad is 50 feet across and each can of paint covers about 200 ft2.

Idon’t understand this.. will someone ? will mark brainliest along with 20 points.

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?