Answer: 15 grams of salt are there in 5 L of solution.
Step-by-step explanation:
Concentration of a solution is defined as the number of grams of solute dissolved per liter of the solution.
Given : Concentration of solution : 3 g/L
1 Liter of solution contains = 3 gram of salt
Thus 5 L of solution contains =

Thus 15 grams of salt are there in 5 L of solution.