Atank contains 400 l of fluid in which 50 g of salt is dissolved. brine containing 2 grams of salt per liter is pumped into the tank at a rate of 5 l/min. the well-mixed solution is pumped out at the same rate. (a) find the number aſt) of grams of salt in the tank at time t. (b) what is the concentration c(t) of the salt in the tank at time t? (c) at what time is the concentration of the salt in the tank two times the initial concentration?

What is the 17th term in the arithmetic sequence in which a6 is 101 and a9 is 83

(50 ) mrs. julien’s and mrs. castillejo’s classes are selling cookie dough for a school fundraiser. customers can buy packages of macadamia nut chip cookie dough and packages of triple chocolate cookie dough. mrs. julien’s class sold 25 packages of macadamia nut chip cookie dough and 30 packages of triple chocolate cookie dough for a total of $221.25. mrs. castillejo’s class sold 5 packages of macadamia nut chip cookie dough and 45 packages of triple chocolate cookie dough for a total of $191.25. (a) write the system of equations that model the problem. be sure to explain which equation represents which situation. (b) find the cost of each type of cookie. show your work. (c) explain which method you used to solve the system and why you chose that method.

How many quarts of a 50% solution of acid must be added to 20 quarts of a 20% solution of acid in order to get a 40% solution of acid?