Mean is adding all them up and then dividing by how many there are. the answer is 12
The first step to determine the function is to find the total cost of the auction. This is done by adding all the prizes and the cost of the food.

The total cost of the auction is $900. Since the cost of 50 tickets should be able to cover the cost, we need to divide the total cost by the number of tickets to determine the cost of each ticket.

Each ticket must be sold as $18. The whole function is:
Simply present that you would split them up as a factor of two. ( make two lines going either vertically or horizontally. place in varriations, a marble in one line and a marble in the other and then count the leftover