alevel organic chemistry help

**A student investigated the extent of hydrolysis in an old sample of the fat in part (a). 
The carboxylic acid extracted from a 2.78 g sample of this fat (Mr = 806.0) reacted with 24.5 cm3 of a 0.150 mol dm–3 solution of NaOH. 
Calculate the percentage of the fat that had hydrolysed. 
Show your working.
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i dont understand this

Hey! I just found this on a thread from 6 years ago lol:
To do this, you first need to know that you need 3 moles of NaOH to hydrolyse the fat to give 1 mole of sodium salt then you would react it with 1 mole HCl to get a carboxylic acid (remember from CHEM4 when making soap).
Since we now know that the ratio of NaOH to the fat is 3:1, we can start to work out the question. This is what I would do next:

Work out the number of moles of NaOH which is the concentration multiplied by the volume (change this to dm3 by dividing by 1000). Hence
n(NaOH)= 0.0245dm3*0.15=3.68*10^-3 moles

Then work out the moles of the fat that is going to be hydrolysed by dividing the moles of NaOH by 3. Hence
n(hydrolysed fat)=(3.68*10^-3)/3=1.23*10^-3 moles

Then I would work out the number of moles of the old sample of fat from its given mass and its Mr. Hence
n(sample fat)=2.78g/806=3.45*10^-3 moles

Finally to find out the percentage, you would divide n(hydrolsed fat) by n(sample fat) and multiply by 100%. Therefore
percentage=(1.23*10^-3)/(3.45*10^-3)=0.357 which is 35.7%