The average age of a husband and a wife is 23 years when they were married five years ago but now the average age of the husband, wife and child is 20 years(the child was born during the interval). What is the present age of the child?
A. 1 year
B. 2 years
C. 3 years
D. 4 years
28 * 2 = 56
20 * 3 = 60
4 years