Mr. Winters borrowed tables and chairs for a party. The number of chairs borrowed by Mr. Winters is 3 times the numbers of tables. If there are 80 legs on the furniture altogether. How many tables and chairs did mr. Winters borrowed?

We can say that the amount of tables borrowed is x, chairs borrowed is y, and total borrowed is z. By the 2nd sentence we can say 3x=y. And assuming every table and chair has 4 legs, we can also say that 4x+4y=80. Using substitution, we can then say that 4x+12x=80, and 16x=80, which simplifies to x=5. Plugging x back in, we get 3*5=y=15. So than x + y is the total, or 5+15, so the answer is 20.