Finite Math... no idea

Question

A group contains 11 women and 9 men (a) Howmanydifferentwayscanfourmenfromthegroupbearrangedinarow? (b) How many ways can four people from the group be arranged in a row? (c) Inhowmanywayscanfivepeoplefromthegroupbearrangedinarowifthefirstthreemustbemenandthelast two women

Answer 1

Four men in a row, order makes a difference, 9 · 8 · 7 · 6 = 3024

Four people in a row, order makes a difference, 20 · 19 · 18 · 17 = 116280

Three men, then two women, 9 · 8 · 7 · 11 · 10 = 55440