We start out with 1/2 pitcher.
They shared 3/4 of that amount that was in the pitcher.
3/4 x 1/2 = 3/8
In total, they shared 3/8 of a pitcher of iced tea.
It says they shared it equally, meaning each of them got half of the 3/8.
1/2 x 3/8 = 3/16
That gives us the answer to:
a) They each drank 3/16 of a pitcher of iced tea.
So, they shared 3/8 of the pitcher. Meaning they drank 3/8 of it. Meaning 5/8 of it is still left in the pitcher. That gives us the answer to:
b) 5/8 of a pitcher of iced tea was left over.