A tank initially contains 120 L of pure water. A mixture containing a concentration of 10 g/L of salt enters the tank at the rate of 2 L/min, and the well-stirred mixture leaves the tank at the same rate. Find an expression for the amount of salt in the tank at any time t. Also find the limit of the amount of salt in the tank as t ! 1.

Martin likes to make flower bouquets that have 3 daffodils and 4 tulips per vase. a daffodil has a mass of d grams, a tulip has a mass of t grams, and the vase has a mass of u grams. the expression 5(3d + 4t + v) describes the mass of 5 bouquets. match each amount in the situation with the expression that represents it. situation expression number of bouquets mass of one bouquet mass of the tulips in one bouquet 4t mass of the daffodils in one bouquet 3d + 4t + v

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.

The price of an item has been reduced by 30%. the original price was $30. what is the price of the item now ?