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The ages of three siblings Jason John and Jackson totals 21 years. Jason is one year older than John. Jackson is three times as old as John. How old is John?

1 Answer

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Answer:Jason is 5 years old.

John is 4 years old.

Jackson is 12 years old.

Explanation:

Let x represent the age of Jason.

Let y represent the age of John.

Let z represent the age of Jackson.

The ages of three siblings Jason John and Jackson totals 21 years. It means that

x + y + z = 21 - - - - - - - - - - -1

Jason is one year older than John. It means that

x = y + 1

Jackson is three times as old as John. It means that

z = 3y

Substituting x = y + 1 and z = 3y into equation 1, it becomes

y + 1 + y + 3y = 21

5y = 21 - 1 = 20

y = 20/5 = 4

x = y + 1 = 4 + 1

x = 5

z = 3y = 3 × 4

z = 12

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