If the present ages of a father and his son are 48 year and 28.8 years old respectively ,then the father can say to his son , I was ________ of your present age when you were born .

Options

A. half
B. three -fifth
C. one -fifth
D. one -third

Answer

To solve the problem, we need to determine the age of the father when the son was born and then express that age in relation to the son's current age.

### Step-by-Step Solution:

1. **Identify the present ages of the father and son:**
- Father's age = 48 years
- Son's age = 28.8 years

2. **Calculate the father's age when the son was born:**
- The age of the father when the son was born can be calculated by subtracting the son's current age from the father's current age.
- Father's age when son was born = Father's current age - Son's current age
- Father's age when son was born = 48 - 28.8 = 19.2 years

3. **Express the father's age when the son was born as a fraction of the son's current age:**
- We need to find out what fraction of the son's current age (28.8 years) the father's age (19.2 years) represents.
- Fraction = Father's age when son was born / Son's current age
- Fraction = 19.2 / 28.8

4. **Simplify the fraction:**
- To simplify 19.2 / 28.8, we can divide both the numerator and the denominator by their greatest common divisor.
- First, we can multiply both by 10 to eliminate the decimal:
- 192 / 288
- Now, we can simplify:
- Divide both by 96:
- 192 ÷ 96 = 2
- 288 ÷ 96 = 3
- So, 192 / 288 simplifies to 2 / 3.

5. **Final Answer:**
- The father can say to his son, "I was **2/3** of your present age when you were born."