Mike O'Malley asked one of his customers how old his son was. The customer replied:
"My son is five times as old as my daughter, and my wife is five times as old as the son, and I am twice as old as my wife, whereas granny, who is as old as all of us put together, is celebrating her 81st birthday today."
So how old is the boy?
here's the answer but don't peek till you've had a good try!
