Question

(you can give youtr als we A tank contains initially (t 0) 200 gallons of water in which 80 pounds of salt are dissolved. Pure water (i.e. no salt) runs into the tank at the rate of 4 gal/min. The mixture is drained out from bottom of tank at the rate of 6 gal/min. How much salt is there in the tank after 66 minutes?

Answer 1

Total water = 200 gallons salt = 80 pounds pure water runs into the tank at the rate of 4 gal/min The mixture drained out from the bottom at the rate of 6 gal/min t = 0 mixture 200 t = 1 mixture 198 because 6 gal drained out from the bottom of the tank and 4 gal of pure water is poured into the tank. Now the salt concentration is 100 % - 6/198 times 100 rightarrow 97 % t = 2 mixture 196 1 the salt concentration is 6/196 times 100 rightarrow 3 % means 3 % decreased from 97 % of the salt concentration t = 3 mixture is 194 now the salt concentration decreased is 6/194 times 100 % = 3 % it means the remaining salt concentration 97 % of the 3 % of the 3% --- is continuous same for all the time at t = 66 the remaining salt concentration is = (0.97)^66 times 80 = 10.716 pounds