Question

At the beginning of hour 1 a large tank contains 1000 liters of brine, consisting of water in which 11kg of salt is dissolved. During each subsequent hour 150 liters of brine is drained from the tank and at the end of each hour is replaced by an equal amount of pure water. How much dissolved salt remains in the tank at the beginning of hour 11?

Answer 1

Beginning of Howrs Brine = 1000 litres Salt = 11 kg Salt per lter Bruine - 11 Beginning of Hour 2 Beine = "1000 Salt - 11 - 150 x 11 1000 = 85x11 100 1000 Salt = 935 kg 100 Salt per litre brine = 935 100x1000 salt left = 900 Beginning of Hour 3 Salt Left = 935 - 935 x 150 Salt left = 435*85 10000 Salt peu litere bruine = 79475 1000 1000 10000x1000 Beginning of Hour 4 Salt left = 79475 - 79475x 45% 10000 100 10000x1000 = 79475 x 85 10000*100 Since at every step salt belt is 0.85 times the forevious house so at Beginning of Hour 5 Salt left = 79475x85x85 Beginning of How 11 29425x85x 85 x 85 x 95 x 25 x 85 x 25x25 - 100 x 100 Salt left = 0.21 66 gm /