Please help me asap

How do you use the elimination method for this question? explain, because i really want to understand!

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.

You spin the spinner shown below once. each sector shown has an equal area. what is p(beaver ) p(beaver)? if necessary, round your answer to 2 2 decimal places.