Nclex prep

I came across the following question while preparing for NCLEX, my answer was wrong and the explanation for the correct answer is very brief, can any body help please? Thank you

A client undergoes peritoneal dialysis. The physician orders 2 liters to be instilled with a dwell time of 40 minutes. The nurse measures the outflow and finds it to be 1,800 mL. During the nurse's shift, the client drinks 700 mL of fluids and voids 400 mL. Record the client’s intake in milliliters.

My answer: 500

intake = 2litters (2000ml) +700ml = 2700ml

out= 1800 + 400ml = 2200ml

The difference between inflow and outflow is considered intake. which is 500ml

Correct answer: 900

Ok... We had this on Kaplan.

So inflow is 2000, outflow is 1800... Therefore, 200 stayed in. Then he drinks 700. That's 900 intake. They are not asking what he put out, only what he took in.

Answer is 900.

Hope this helps.

Got it thank you