Need help on these 2 questions!

Trent wants to buy 2 packs of trading cards for 3 dollars each. the trading card packs that trent normally buys tend to come in packs of 6, 10, 12, or 15 cards. after selecting 2 packs, trent found that the first pack of cards cost 25 cents per card, and the second pack cost 30 cents per card. trent uses this information to write the equations below in order to compare c, the number of cards in each pack.

What are the coordinates of the point that is 1/3 of the way from a to b? a (2,-3) b (2,6)

If there is 20 dogs in the shelter and 5 dogs get homes, and then 43 more dogs come. how many dogs are there in the shelter?