Pls help! i need the answer by maybe an hour please!

In the following situation, determine whether you are asked to determine the number of permutations or combinations. then do the calculation how many ways are there to pick a starting five from a basketball team of twelve members? a. permutation; ps - 2520 b. combination; 1c, - 792 c. combination: 2cs - 2520 d. permutation; ps - 95040

Given a: b and b: c, find a: b: c. write the ratio in simplest form. a: b=6: 10 and b: c=21: 33

Two numbers have a sum of -19. one number is x. what expression represents the other number?