Is this a linear function?

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.

To determine the number of deer in a forest a forest ranger tags 280 and releases them back

The measures of the legs of a right triangle are 15m and 20m . what is the length of the hypotenuse