Given:
The selling price of 12 eggs is equal to the cost of 15 eggs.
To find:
The gain percentage.
Step-by-step explanation:
Let us assume the cost price of 1 egg is $1.
So, the cost price of 15 eggs is $15.
According to the problem,
The selling price of 12 eggs is $15.
So, the selling price of 1 egg is,
Then, the gain percentage is,
Therefore, the gain percentage is 25%.
Final answer:
The gain percentage is 25%.