have a problem to solve for my new game game. really appreciate if someone can help me solve this issue:

* i need to calculate the probability for a given combination

1. Total number of balls in the box = 80

2. Total number of chosen balls 45

3. for simplicity we have only 1 card 5x5 (25 numbers in total)

question

what is the probability that i will get

a. 4 corners of the card?

b. any row ?

c. any 2 rows?

if someone can give me a start i will be happy