High School

We appreciate your visit to The sum of Mrs Lim s age and her son s age is 80 years now Mrs Lim was 4 times as old as her. This page offers clear insights and highlights the essential aspects of the topic. Our goal is to provide a helpful and engaging learning experience. Explore the content and find the answers you need!

The sum of Mrs. Lim's age and her son's age is 80 years now. Mrs. Lim was 4 times as old as her son 5 years ago. How old was Mrs. Lim's son 5 years ago?

Answer :

To solve the problem of finding how old Mrs. Lim's son was 5 years ago, we need to set up a system of equations based on the information given.


  1. Define the variables: Let [tex]x[/tex] be the current age of Mrs. Lim's son. Then, the current age of Mrs. Lim is [tex]80 - x[/tex].


  2. Write the equation for the past situation: 5 years ago, Mrs. Lim was 4 times as old as her son. Therefore, Mrs. Lim's age 5 years ago was [tex](80 - x - 5)[/tex] and her son's age was [tex](x - 5)[/tex].

    So, we have the equation:
    [tex]80 - x - 5 = 4(x - 5)[/tex]


  3. Simplify the equation:
    [tex]75 - x = 4(x - 5)[/tex]

    Expand the right side:
    [tex]75 - x = 4x - 20[/tex]


  4. Solve the equation for [tex]x[/tex]:
    [tex]75 + 20 = 4x + x[/tex]
    [tex]95 = 5x[/tex]
    [tex]x = \frac{95}{5} = 19[/tex]


  5. Find the age 5 years ago:
    [tex]x = 19[/tex] is the current age of Mrs. Lim's son. Thus, 5 years ago, he was:
    [tex]19 - 5 = 14[/tex]



Therefore, Mrs. Lim's son was 14 years old 5 years ago.

Thanks for taking the time to read The sum of Mrs Lim s age and her son s age is 80 years now Mrs Lim was 4 times as old as her. We hope the insights shared have been valuable and enhanced your understanding of the topic. Don�t hesitate to browse our website for more informative and engaging content!

Rewritten by : Barada