It is closely related to biology.

The relationship between hair color and age.

Subordinates know the manager's age,

As long as 13 is divided into three numbers,

There are many possibilities that the product of three numbers equals the manager's age.

So,

The reason why subordinates can't guess the answer is:

Lack of additional conditions,

The ternary equation has no definite solution and must be transformed into a binary equation.

Assuming there are no twins among the three daughters,

Then the age difference between three people should be greater than a value (biological common sense)

Black hair is the dominant gene,

If the manager and his wife are not brunettes, then the brunette girl is. ...

There is only one fact:

There are no twins among the girls,

But no two girls are the same age!

Then,

Solve binary equation

Obviously, the age of the three daughters is not 0, or the father will be 0, so the age of the daughters is 1. In this way, we can get the following results:1*11,1*2** 10=20, 1 * 3 *. {2 * 2 * 9 = 36}, 2 * 3 * 8 = 48, 2 * 4 * 7 = 56, 2 * 5 * 6 = 60, 3 * 3 * 7 = 63, 3 * 4 * 6 = 72, 3 * 5 * 5 = 75, 4 *.