Total teachers except those who teach English and Science = (50/100) × 2400 = 1200 Number of teachers who teach English = 15% = (15/100) × 2400 = 360 New number of teachers who teach English = 360 + (25/100) × 360 = 450 Number of teachers who teach Science = 35% = (35/100) × 2400 = 840 New number of teachers who teach Science = 840 – (10/100) × 840 = 756 Initial number of all teachers together = 2400 New number of all teachers together = 1200 + 450 + 756 = 2406 Increase in number of teachers = 2406 – 2400 = 6 Percentage increase = (6/2400) × 100 = 0.25%