Answer: The volume of stock solution needed is 1.5 L
Step-by-step explanation:
To calculate the molarity of the diluted solution, we use the equation:

where,
 are the molarity and volume of the stock solution
 are the molarity and volume of the stock solution
 are the molarity and volume of diluted solution
 are the molarity and volume of diluted solution
We are given:

Putting values in above equation, we get:

Hence, the volume of stock solution needed is 1.5 L