An examination consists of two papers of 140 marks and 150 marks. A candidate scored 35% marks in the first paper of 140 marks. What percent marks should be obtained by him in the second paper so as to score 50% marks in the two papers together?

In a town with 30,000 professionals, teachers make up 11% of the total professionals. If 46% of teachers are male, what is the number of female teachers in the town?

In a town's professional breakdown, doctors represent 18% and clerks represent 8% of the total professionals. If the number of doctors is 3000 greater than the number of clerks, what is the total number of professionals in the town?