a store sells hats for 10 dollars. The store pays 6 dollars per hat and bought an embroidery machine for 72 dollars to customize each hat. How many hats must they sell to make a profit?

one hat- 10 dolar -for one hat 6  dolars payed -> 4 dolars profit per hat

4n>72 -> n > 72/ 4 -> n> 18

the store must sell more than 18 hats