Answer:
23 students
Step-by-step explanation:
In a group of students , 12 read maths, 15 read statistics , 11 read physics, 4 read maths only , 7 read statistics only, 3 read statistics and physics only and 1 read maths and statistics only.
Those that read maths only = 4, Those that read statistic only =7, Those that read statistics and physics only = 3, those that read maths and statistics only = 1.
Therefore those that read all three subjects = 15 - 7 - 3 - 1 = 4
Those that read maths and physics only = 12 - 4 - 4 - 1 = 3
Those that read physics only = 11 - 3 - 4 - 3 = 1
The number students = 4 + 7 + 3 + 1 + 4 + 3 + 1 = 23 students
