A vendor pays a rock band 13 of the total profit from T-shirts and sweatshirts sold at every concert. The vendor paid the rock band $726 after the last concert. If the profit from T-shirts sales was $1,632, what was the profit from sweatshirt sales?

Let's call

x = profit from the sweatshirt sales

1) A vendor pays to rock band 13% of the total profit from T-shirts and sweatshirts sold at every concert.

2) the profit from T-shirts sales was $ 1,632

3) The vendor paid the rock band $ 726 after the last concert

We then have the following equation:

0.13 * (1632 + x) = 726

Clearing x:

(1632 + x) = (726 / 0.13)

x = (726 / 0.13) - 1632 = 3953 $

Answer:

the profit from sweatshirt sales was 3953 $