Answer:
54 years old
Explanation:
First, lets define the man's age.
Let the man be x years old.
The man is 3 times the as old as his son.
Therefore, his son is 1/3 of the man's age.
Then his son must be 1/3 x.
The man is twice as old as his daughter.
Therefore, his daughter is 1/2 of the man's age.
Then his daughter is 1/2 x.
Now, we shall find find their total age in term of the variable x.
Total age = x + 1/3 x + 1/2 x = 11/6 x
We are also given that the average of the three people is 36 1/3 years.
With the average age, we can find the their total age.
Total age = 36 1/3 x 3 = 109/3 x 3 = 109 years.
With these information, we are ready to solve x.
11/6 x = 109
x = 54 years old (nearest year )