At first glance, this family puzzle looks like a simple counting question.
But there is a small detail in the wording that can easily make you choose the wrong answer.
Take a moment to read the puzzle carefully before doing any math.
Mr. Wang and Mrs. Wang have 3 sons.
So, the first people we can count are the parents and their three sons.
That gives us 5 people so far.
Now the puzzle says that every son has 1 wife.
Since there are three sons, each one has his own wife.
That means we add 3 wives to the family.
Now our total is 8 people.
Next comes another important detail.
Every son also has 1 son.
There are three sons in the next generation, one belonging to each of the three original sons.
So we add 3 more people.
That brings the total to 11 people.
At this point, many people may be tempted to choose B. 11.
But we still have one more detail to consider.
The puzzle says that every son has 1 sister.
This is where the wording becomes important.
It does not say that each son has a different sister.
The three brothers can all have the same sister.
For example, imagine Mr. and Mrs. Wang have four children: three boys and one girl.
Each of the three boys would have one sister.
But that sister is the same person for all three brothers.
So we only need to add one sister, not three sisters.
That brings our final total to 12 people.
Let’s check the family one more time so there is no double-counting.
Mr. Wang and Mrs. Wang make 2 people.
Their three sons make 3 people.
The three wives of those sons make another 3 people.
The three sons of those sons make another 3 people.
And the three brothers share one sister, adding 1 person.
So the calculation is:
2 + 3 + 3 + 3 + 1 = 12
Therefore, the correct answer is C. 12.
The trick is not really difficult math.
It is about understanding the relationship between the people and avoiding counting the same person more than once.
If each brother had a different sister, the answer would be higher.
But the puzzle never says that.
In a normal family, several brothers can obviously have the same sister.
That is why one sister is enough to satisfy the statement that every son has 1 sister.
This is also why 11 is so tempting.
You can get to 11 quite easily, but you may forget that the three brothers still need a sister.
On the other hand, choosing 14 usually means assuming that each son has a different sister, which the puzzle never tells us.
So the key is to slow down and think about the wording rather than simply adding every number you see.
