Three years ago, the average age of A and B was 18 years. With C joining them, the average age becomes 22 years. How old is C now?	Choices:
A) 20 years B) 24 years C) 27 years D) 30 years E) None
Sol.   Present age of ( A + B) = ( 18 × 2 + 3 × 2) years = 42 years.   Present age of ( A + B + C) = (22 × 3) years = 66 years.   Therefore C’s age = (66 – 42) years   = 24 years.   Answer 24 years
<result>B</result>
Three years ago, the average age of A and B was 18 years. With C joining them, the average age becomes 22 years. How old is C now?