Multiple choice

A man is $42$ years old and his son is $12$ years old. In how many years will the age of the son be half the age of the man at that time?

  1. $13$ years
  2. $18$ years
  3. $14$ years
  4. $19$ years
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Let x be the number of years. (42 + x) / 2 = 12 + x. 42 + x = 24 + 2x. x = 18.

AI explanation

Let the number of years be t, so the age of the son will be 12 plus t and the age of the man will be 42 plus t. The condition requires the son's age to be half the man's age, giving the equation 12 plus t equals half of 42 plus t. Multiplying by 2 gives 24 plus 2t equals 42 plus t, so t equals 18. The age of the son will be half the man's age in 18 years.

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