Two groups of students at the convenience store bought the same sort of granola bars and
coffees. The first group, together, bought 4 granola bars and 6 coffees, spending $31 in all
The second group bought 7 granola bars and 4 coffees, spending $31.50 in all.
What is the cost of a single granola bar and a single coffee?

In the diagram of circle a what is m

For what values of the variable x is the expression square root of 7x+14+ square root of 7-x a real number?

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?