Better help me with this because i have a 10 minute timer and it is graded

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.

I’ve been trying all day to figure this puzzle out. i need the work for it aswell. it is a factoring polynomials tarsia. the image is below.

Solve for x: 5/3 x = 20/21 it's fraction. remember to simplify your fraction