For this question below :
Assume that the EUR:USD six-month forward exchange rate is quoted at 1.2102 − 1.2112. What is the bid-ask spread as a percentage of the ask price based on a direct quote for euros?
you take the inverse, I get that, but does the bid now become the ask? see the answer explanation below from schweser:
Our quote is in terms of the number of dollars per euro, and a direct quote for euros is the number of euros per dollar. So, we must invert the rates given to get USD:EUR = 0.8256 − 0.8263. The spread is the difference between the bid and the ask or 0.8263 − 0.8256 = 0.0007. The spread as a percent of the ask price is (0.0007 / 0.8263) or 0.0847%. Rounding is per market convention.