Calculate the amount (mol) of solute delivered to the dilute solution. 2.00 ml of 0.0400 m solution was added.

Molarity is defined as the number of moles of solute in 1 L of the solution
In this instance a certain volume is taken from the given solution with molarity of 0.0400 M and diluted. Then the moles of solute is dissolved in a larger volume of water and concentration becomes lesser in other words it’s diluted
Number of moles of solute in 2.00 mL needs to be calculated
Number of solute moles in 1000 mL - 0.0400 mol
Then number of moles in 2.00 mL - 0.0400 mol / 1000 mL x 2.00 mL = 0.0000800 mol
Number of moles of solute added = 0.0000800 mol