Answer:
74.4mL
Explanations:
Given the reaction between citric acid and baking soda expressed as:

Given the following parameters
Mass of baking soda = 15grams
Determine the moles of baking soda

According to stoichiometry, 1 mole of citric acid reacted with 3 moles of baking soda, the moles of citric acid required will be:

Determine the volume of citric acid

Hence the required volume of citric acid is 74.4mL