Question 886737
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.