Question: If the present age of a father is 45 years and his son is 15 years old, in how many years will the father be twice as old as his son?

Options:

1. 10
2. 15
3. 20
4. 5

Correct Answer: 10

Solution:

Let the number of years be x. In x years, the father\'s age will be 45 + x and the son\'s age will be 15 + x. The equation is 45 + x = 2(15 + x), which simplifies to 45 + x = 30 + 2x, so x = 15.