On their wedding day the average age of a couple was 27 years. Today they have a daughter of 4 and a son of 2, and the average age of the four of them is 22 years. How many years ago did the couple marry?

On the wedding day the couple totalled $2\times 27=54$ years. After $t$ years they total $54+2t$, and with the children the family totals $54+2t+4+2=60+2t$. Today that must equal $4\times 22=88$, so $2t=28$ and $t=14$. Check: the couple total 82 today, plus 6 for the children makes 88, and 88/4 = 22. 28 is the intermediate $2t$. 7 comes from ageing all FOUR over the whole span $(60+4t=88)$, but the children were not there for those 14 years. 22 repeats today's family average.