The average age of 60 students in a class is 18 years. The average age of a group of 25 boys is 20 years and the average age of a group of 25 girls is 17 years. What is the average age of remaining students of the class?
1
15.5 years
2
14.5 years
3
16.5 years
4
15 years
5
12 years