Răspuns:
100g sol..............1og soda
400g.......................md1
md1=10x400/100=40g
100g........................50g
400g.........................md2
md2=400x50/100=200g
ms=400+400+200=1000g
md=40+200=240
1000g.............................240g soda
100g..................................c
c=24
Explicație: