Omar and Meg just had business cards made. Omar's printing company charged a one-time setup fee of $5 and then $5 per box of cards. Meg, meanwhile, ordered hers online. They cost $4 per box. There was no setup fee, but she had to pay $10 to have her order shipped to her house. By coincidence, Omar and Meg ended up spending the same amount on their business cards. How many boxes of business cards did each buy?