Ask questions and get helpful answers.

a father is three times as old as his son, and his daughter is 4 years younger than his son. if the sum of all three ages 3 years ago was 72 years, find their present ages

  1. 👍
  2. 👎
  3. 👁
  4. ℹ️
  5. 🚩
1 answer
  1. F = present father's age

    S = present son's age

    D = present daughter's age

    A father is three times as old as his son, and his daughter is 4 years younger than his son means:

    F = 3 S , D = S - 4

    3 years ago father was F - 3 yrs old

    Son was S - 3 yrs old

    Daughter was D - 3 yrs old

    The sum of all three ages 3 years ago was 72 years means:

    F - 3 + S - 3 + D - 3 = 72

    Replace F with 3 S

    and replace D with S - 4

    in this equation.

    3 S - 3 + S - 3 + S - 4 - 3 = 72

    5 S - 13 = 72

    Add 13 to bith sides.

    5 S = 85

    S = 85 / 5

    S = 17 yrs old

    F = 3 S = 3 • 17 = 51 yrs yrs old

    D = S - 4 = 17 - 4 = 13 yrs old

    Check result:

    3 yrs ago father was 51 - 3 = 48 yrs old

    Son was 17 - 3 = 14 yrs old

    Daughter was 13 - 3 = 10 yrs old

    The sum of all three ages 3 years ago was:

    48 + 14 + 10 = 72 yrs

    1. 👍
    2. 👎
    3. ℹ️
    4. 🚩

Answer this Question

Related Questions

Still need help?

You can ask a new question or browse existing questions.