Final answer:
The balloon seller's problem is a basic algebra question where an equation is formed using the given conditions related to the sale of balloons. By setting up the equation and solving for 'x', the initial number of balloons, we find that the seller started with 60 balloons.
Step-by-step explanation:
The balloon seller's problem can be represented by a simple algebraic equation. Let's call the total number of balloons the seller starts with 'x'. According to the question, he sells one third to boys, which is x/3, and 20% (which is the same as 1/5) to girls, which is x/5. The next piece of information is that he sells three times the difference between the number sold to boys and the number sold to girls to adults. So, that is 3(x/3 - x/5) balloons.
Now, we can build our equation. At the end of the day, he has 8 balloons left, which means:
x - x/3 - x/5 - 3(x/3 - x/5) = 8
By finding a common denominator and simplifying the equation, we can solve for 'x' to find out how many balloons he had at the start. Calculating through these steps reveals that the balloon seller started with 60 balloons.