A solution contains 250 mL of water and 50 mL of salt. If you add 150 mL more water, what is the new concentration of salt as a percentage?
Answer
12.5 percent
How to solve it
1
Initial: 250 mL water + 50 mL salt = 300 mL total
2
After adding water: 400 mL total (salt stays 50 mL)
3
Concentration: (50 ÷ 400) × 100 = 12.5%
Hints
Find new total volume
Salt amount stays the same
Divide salt by new total