Mark:
CENSUS
8, 3, and 3
Ok! How could Mark have known the ages when the question did not even give the house number? Well, one way is:
The ages of the three children must be 3, 3, and 8, and the address is 14.
The following are the only combinations of three ages whose product is 72:
Code:
1st Child 2nd Child 3rd Child Sum of Ages
1 1 72 74
1 2 36 39
1 3 24 28
1 4 18 23
1 6 12 19
1 8 9 18
2 2 18 22
2 3 12 17
2 4 9 15
2 6 6 14
3 3 8 14
3 4 6 13
Except for two of the combinations, their sums are all different, so the census worker would have been able to determine the ages of the children if the address had been any of the different ones.
As she needed more information, however, the address must have been 14, a total shared by two combinations: 2, 6, 6, and 3, 3, 8. So when the father indicated that he had an oldest child, she eliminated the first possibility, which had two "oldest," leaving only 3, 3, and 8 as the answer.
Four couples assembled together
To share an afternoon meal.
They gathered around a round table
Piled high with roast beef and veal.
Though every man sat between two women,
No man sat next to his mate.
From the following clues that I give you,
Can you figure where each of them ate?
Tyrone sat across from the pilot
And next to demure Mrs. Tewes.
George's wife worked each day as a jeweler
And he spent his time selling shoes.
Delane, he taught shorthand and typing.
The author was named Mary Jane.
Harry sat facing the doctor
And at left of sweet Mrs. Delane.
Mr. Tewes had his dinner alongside
The photographer and Betty Kay.
Loretta's name was Van Allen,
The only blonde was Renee.
Ed sat to the right of a Collins.
A lawyer was one of the bunch.
From only the clues I have given,
Can you figure where each one ate lunch
By filling in the following seating chart?
.1
8
..2
7
3
.6
.4
..5
. 
