Complex sentence: When Major Regan from GHQ inspects the platoon, he decides that Jones must resign, on account of being too old; he also says that if Jones completes an assault course in 15 minutes, he can stay.
Split into simpler sentences: When Major Regan from GHQ inspects the platoon, he decides that Jones must resign, as he is too old. But d; he also says that if Jones completes an assault course in 15 minutes he can stay.