Complex sentence: Approximately 180 pupils are admitted to Year 7 (aged 11 or 12) annually on the basis of competitive examination, with 20 of the places reserved for students with exceptional musical talent.
Split into simpler sentences: Approximately 180 pupils are admitted to Year 7 (aged 11 or 12) annually. Place are awarded on the basis of competitive examination, though 20 are reserved for students with exceptional musical talent.