WBCS.LIVE practice question

The difference of mother's age and her daughter's age is 21 years and the \frac{1}{12} part of the product of their ages is less than the mother's age by 18 years. The daughter's age is

Solve this multiple-choice question and check the correct answer with its explanation below.

Answer options

  1. 2 years
  2. 3 years
  3. 4 years
  4. 1 year

Correct answer and explanation

Correct answer: 3 years

Explanation: āœ… Correct Answer: B. 3 years šŸ“š Explanation: Let the mother be M and the daughter be D. We have M - D = 21 and (1/12) * M * D = M - 18. Substituting M = D + 21 into the second equation creates a quadratic. Solving the equation (D + 21) * D = 12 * (D + 3) gives D = 3. Therefore, the daughter's age is exactly three years old.