Multiple choice

At present, the ratio of the ages of a father and his son is 9 : 4. However, after 5 years, the ratio will become 2 : 1. What is the present age of the father?

  1. 63 years

  2. 45 years

  3. 40 years

  4. 54 years

  5. 55 years
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Let ages be 9x and 4x. After 5 years: (9x+5)/(4x+5) = 2/1. 9x+5 = 8x+10, so x = 5. Father's age = 9*5 = 45.

AI explanation

Let the present ages of the father and son be 9x and 4x years respectively. After 5 years, their ages will be 9x + 5 and 4x + 5, so we can write the equation (9x + 5) / (4x + 5) = 2 / 1. Solving this equation yields 9x + 5 = 8x + 10, which means x = 5. The father's present age is therefore 9 * 5 = 45 years.

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