Spot rate vs. Forward rate

[PassOrNothing]

In regards to spot rate vs. forward rate questions, how would I know which currency would be on the numerator vs. denominator? The actual question is as follows: (Thanks!)
Q1)
If the current spot exchange rate for quotes of JPY/GBP is greater than the no-arbitrage 3-month forward exchange rate, the 3-month GBP interest rate is:
The correct answer was B) greater than the 3-month JPY interest rate.
. If the no-arbitrage forward JPY/GBP rate is less than the spot rate, the interest rate for JPY must be less than the interest rate for GBP.

 

[S2000magician]

If you write it this way, it’s easier to remember:
spot(JPY/GBP) × (1 + rJPY) / (1 + rGBP) = forward(JPY/GBP)
The quote (spot or forward) has JPY in the numerator and GBP in the denominator. JPY grows at the JPY rate, so to get from the spot (with JPY in the numerator) to the forward (with JPY in the numerator), you have to multiply the numerator by (1 + rJPY). GBP grows at the GBP rate, so to get from the spot (with GBP in the denominator) to the forward (with GBP in the denominator) you have to multiply the denominator by (1 + rGBP).