7 pupils of average age 12 years leave a class of 25 pupils of average age 14 years. If 6 new pupils of average age 11 years join the class, what is the average age of the pupils now in the class?

• A.13 years
• B.12 years 7 1/2 months
• C.13 years 5 months
• D.13 years 10 months
• E.11 years