How Old Is John Now?

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In summary, John is currently 8 years old. His father is 40 years old (5 times older than John) and his sister Alice is 4 years old (twice as old as John). In two years time, John will be 10, his father will be 42, and Alice will be 6. The sum of their ages will then be 58.
  • #1
mathdad
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John’s father is 5 times older than John and John is twice as old as his sister Alice. In two years time, the sum of their ages will be 58. How old is John now?

John's dad = 5(2x)

John = 2x

Alice = x

5(2x) + 2 + 2x + 2 + x + 2 = 58

10x + 3x + 6 = 58

13x + 6 = 58

Correct so far?
 
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  • #2
Yes. Why didn't you solve for x and use that value to compute John's age? :)

Will you try rewriting the system so John's age is the variable?
 
  • #3
John's dad = 5(2x)

John = 2x

Alice = x

5(2x) + 2 + 2x + 2 + x + 2 = 58

10x + 3x + 6 = 58

13x + 6 = 58

13x = 58 - 6

13x = 52

x = 52/13

x = 4

John = 2x

John = 2(4)

John is 8 years old.
 

FAQ: How Old Is John Now?

What is the current age of John?

Unfortunately, without more information about John, I cannot accurately determine his current age. It would depend on his birth date and the current date.

How do I calculate John's age?

To calculate John's age, you would need to know his birth date and the current date. Subtract his birth date from the current date to determine his age in years.

Is John older or younger than a certain age?

Without knowing John's birth date, I cannot say for sure if he is older or younger than a certain age. However, if you provide his birth date and the age you are comparing to, I can calculate and determine the answer.

What is the average age of people named John?

The average age of people named John would vary depending on the data set used. It could be calculated by finding the sum of the ages of all people named John and dividing by the total number of individuals in the data set.

Can you estimate John's age based on certain characteristics?

I am a scientist, not a psychic, so I cannot estimate John's age based on characteristics alone. Age can vary greatly among individuals and cannot be accurately determined without more information.

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