Small Nav Q
I would be most grateful for an explanation as to the solution of the below. Thank you in advance for your help.
Given ETA to cross a meridian is 2100 UTC, GS is 441 kts, and TAS is 491 kts. At 2010 UTC ATC requests a speed reduction to cross the meridian at 2105 UTC. The reduction to TAS will be approximately:
a) 90kt
b) 40kt
c) 60kt
d) 75kt