If you need up to 10 volunteers, then you can take 10 or less. If we add y and x, we'll get the total amount of people, therefore making the inequality:
x + y ≤ 10.
Now, he needs no fewer than 4 females, so he can take 4 or greater. This means that x should be greater than or equal to 4.
x ≥ 4.
Nothing was mentioned about how many males he needed (y) so these two inequalities match the situation.
