A gift shop sells souvenir magnets. The store is selling 3 magnets for $10. At this price, how much will it cost to buy 8 magnet?

I pretty sure the answer to the first question is 3,000. I got this by adding the 272 more Carter got to the 764 and then adding the 764 that Jack collected. I then got 1,800. I divided it by 3 cause it was 3/5 of the final project. I got 600 from that. The I did 600 times 5 and got 3,000. I don't know if it's right but it might help...