What is the ECF Volume?

10g of inulin is injected IV and after equilibrium the concentration of inulin in plasma is 50mg/100ml.if 10% of the inulin is excreated,what is the ECF Volume?
A.1.8L[23%]
B.18L[63%]
C.2.4L[11%]
D.24L[3%]

In exam if they ask ICF volume then
ICF=TBW-ECF
& TBW MALE =body weight0.6
TBW femALE =body weight
0.5