ExampleThe age of Willis is times the age of his younger brother Arnold 5 years hence, Willis would be equal to times Arnold’s.. Find their ages.

Solution :

Let 'x years' be Arnold’s present age

Willis is times Arnold, therefore the age of Willis is x years.

Now we set up the equation as

5 years hence
Willis’ age would be equal to times Arnold’s age then
                    

By multiplying by 6 throughout , we get

9 x + 30 = 8 x + 40

9 x - 8 x = 40 - 30

x = 10

Therefore, Arnold’s present age is 10 years. Willis’s present age is 15 years

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Index

9.1 - Definition and Solving Techniques
9.2 - Use of Simultaneous Linear Equations

Chapter 1