Final answer:
By setting up an algebraic equation, we concluded that the ice cream stand collected $400 on Friday, based on the information that Saturday's sales were four times higher, totaling $1600.
Step-by-step explanation:
The question involves solving a basic algebra problem where we need to find out how much money was collected by an ice cream stand on a Friday given that it earned a certain amount on Saturday. According to the information given, the sales on Saturday were four times the amount of sales on Friday. If the total sales on Saturday were $1600, then we can set up the following equation where F represents Friday's sales:
4 × F = $1600
To find F, we divide both sides of the equation by 4:
F = $1600 / 4
F = $400
Thus, the ice cream stand collected $400 on Friday.