CFA equity book page 446, problem 13

I am not sure on page 446, problem 13, how did they get Investment in WC= 41m? Thanks,

WC Assets - Liabs. Add Inventory + AR - (AP + any other short term liab). do not forget to exclude Cash and ST Marketable instruments on the assets side.

Thanks CP, I understood this later as I was blank for a short time.