Which expression correctly represents 10 times the difference of a number and six

How can we find the measure of an exterior angle if we know the measurement of an interior angle

If there are 12 moths and some have 31 days and others have 30 days how many have 28 days?

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.