Need the algebraic expression of 24 less than double x

When you have 25 numbers, and jake picks 3 random numbers and puts them back, what is the chance bob has of picking those 3 numbers when he picks 6 random numbers (without putting them back)? explain.

Which will form a composite function?

Use the quadratic function to predict f(x) if x equals 8. f(x) = 25x2 − 28x + 585