A group of three friends, K, L and M, are sitting in a cafe. Their average age is 24 years. Another friend ‘N’ joins the group and the new average age of the group becomes 23 years. If another friend ‘R’, whose age is 2 years more than that of ‘N’, replaces ‘K’, then the average age of L. M, N and R becomes 22.5 years. What is the age of K?_x005F_x000D_

• A. 15 years
• B. 10 years
• C. 12 years
• D. 14 years