Question

how much salt musy be added to 60 litres of a 20% solution of salt to increase it to a 40% solution of salt?

Answer 1

uation: salt + salt = salt 0.20*60 + 1*x = 0.40(60+x) ----- Multiply thru by 100 to get: 20*60 + 100x = 40*60 + 40x ----- Subtract 40x from both sides Subtract 20*60 from both sides ------ 60x = 20*60 ---- x = 20 litres (amt. of concentrated salt solution to add)