SOLUTION: Maria and Jose invested $20 in drink mix,sugar, and paper cups and opened a stand in front of their house one hot summer day. After four hours of business,they had collected $24.As

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Question 886737: Maria and Jose invested $20 in drink mix,sugar, and paper cups and opened a stand in front of their house one hot summer day. After four hours of business,they had collected $24.Assume that they sell the drinks at the same rate all day.

For the formula,define a variable for the number of hours of the sale and use this variable to write a rule for their profit.
Answer by Theo(13342) (Show Source):
You can put this solution on YOUR website!
they invested $20 in material.
after 4 hours they sold $24.00 worth.
let x = sales per hour.
you get:
4x = 24
solve for x to get:
x = 6
they are selling at the rate of 6 dollars per hour.
in an 8 hour day, they will have sold 8 * 6 = 48 dollars worth of good.
their profit at the end of the day would be equal to 48 - 20 = 28 dollars.
the formula for profit after x hours would be:
p = 6x - 20
the 20 is a fixed cost.
the 6x is the revenue that they earn for x hours of work.
profit is equal to revenue minus cost.

there would be a limit to the number of hours for 20 dollars worth of material since eventually they would run out of material to sell.