Question id 192 - Aircraft General Knowledge - PPL(H) - Private Pilot License

Subtracting 2 % of the CAS for every 1000 ft altitude.
Adding 2 % of the CAS for every 1000 ft altitude.
Subtracting 10 % of the CAS for every 1000 m altitude.
Adding 10 % of the CAS for every 1000 ft altitude.