Answer: 9 eggs were left.
Explanation:
A dozen eggs usually mean there are 12 eggs. We have two ways to solve the problems.
First way:
The egg used to make breakfast: 12 x 25% = 12 x 0.25 = 3
The eggs were left: 12 - 3 = 9
Second way:
12 x (1 - 0.25)
= 12 x 0.75
= 9