When a certain limit on dividends is being remitted back

Suppose a subsidiary sends 50% of it’s post tax profits back home, when we calculate the extra tax payable in the home country do we do Profit before tax*exchange rate*extra tax payable or do we have to divide the PBT by 2 and then do it?

Because in Kaplan – we have divided it by two and at the same time when I look at exam kit questions – its not divided by 2

Please help!