Question

In 2001 Arnold was x years old. Ken is 34 years younger than Arnold. In 2013 Arnold is three times as old as Ken. Write down an equation in x and solve it.​

Answer 1

x = 54

Explanation:

x/3 = x-36

x= 3x-36.3

2x= 36.3

x = 18.3

x = 54

Answer 2

• (x +12) = 3((x -34) +12)
• x = 39

Explanation:

The given age ratio is valid 12 years after the age at which Arnold was x years old. When Arnold was x, Ken was x-34.

(x +12) = 3((x -34) +12) . . . . . the age relation in 2013

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Solving for x, we have ...

x +12 = 3x -102 +36

78 = 2x . . . . . . . add 66-x

39 = x

In 2001, Arnold was 39 years old.

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Additional comment

In 2001, Arnold was 39 and Ken was 5. Ken is 34 years younger.

In 2013, Arnold was 51 and Ken was 17. Arnold was 3 times Ken's age.