Q) What amateur band are you using if you are transmitting on 223.50 MHz?
A) 1.25 meter band
NJ2X Note:
You can memorize this answer. Alternatively, you can learn and apply the underling theory which will help you beyond the test. The relationship between a radio signal's frequency and its wavelength is described by the following formula:
wavelength in meters = 300 / frequency in MHz
In the example above, wavelength = 1.34m = 300 / 223.50Mhz. On the test, the closest answer to the calculated wavelength is the 1.25m band.