Question

how much salt must be added to 60litre of 20% solution of salt to increase it to 40 % of solution of salt?

Answer 1

20/100*60+x = 40/100(60+x)

12+x = 24+2x/5

x-2x/5 = 24-12

3x/5 = 12

3x = 60

x = 20 kg

Therefore more 20 kg of salt should be added