Converting WEBI Logic into BEx Query Designer Formula Variable

Hi All,

I am having problem to convert these WEBI logic into BEx formula variable logic.

1) =If(DaysBetween([Act Goods issuedate];[Requested deliv.date]) >=0;1;0)

2) =If (Count([Delivery date (ReqDate)])) =1 Then 1 Else 0

3) =If ([Delivery quantity]/[Orderquantity]) >= 0.9 Then 1 Else 0

I will appreciate if someone just converts theses logics into BEx Query Designer Variables and provide some steps for
future understanding that how to convert logic in BEx format.

Thanks

Asghar