If John is x years old now, and his father is 44 years old now, in how

Question

If John is x years old now, and his father is 44 years old now, in how many years will John’s father be twice as old as John will be at that time?

A. 44 – 2x
B. 44 – x
C. 44
D. 2x
E. x – 22

PS21252

BrentGMATPrepNow · Answer

GIVEN: 
x = John's PRESENT age
44 = the father's PRESENT age

Let k = the number of years it will take until John's father is TWICE as old as John

So....
x +   k   = John's age IN k YEARS
44 +   k   = the father's IN k YEARS

In k years, we want the father's age to be twice John's age
In other words we want: 44 +   k   = (2)(x +   k  )
Expand to get: 44 + k = 2x + 2k
Subtract k from both sides to get: 44 = 2x + k
Subtract 2x from both sides to get:  44 - 2x = k

In other words, in  44 - 2x  years, the father's age will be twice John's age

Answer: A

Cheers,
Brent

Abhishek009 · Answer

2( x + n ) = 44 + n

Or,  2x + 2n = 44 + n

Or,   n = 44 - 2x , ANswer must be (A)

ScottTargetTestPrep · Answer

Let n = the number of years that will pass until John’s father will be twice as old as John will be at that time. We see that John’s father will be (44 + n) and John will be (x + n); the relationship between the two ages will be that John’s father is twice as old. Thus, we have:

44 + n = 2(x + n)

44 + n = 2x + 2n

44 - 2x = n

Answer: A

EgmatQuantExpert · Answer

Solution

Given  
In this question, we are given that
 • John is x years old now, and 
• His father is 44 years old now

To find  
We need to determine
 • In how many years will John’s father be twice as old as John will be at that time

Approach and Working out  
Let us say after y years John’s father age will be twice that of John’s
 • Age of John after y years = x + y
• Age of his father = 44 + y
• Thus, 44 + y = 2(x + y)
 o Implies, y = 44 – 2x

Thus, Option A is the correct answer.

Correct Answer: Option A

Basshead · Answer

John's present age = x
Father age = 44

y = years from now

44 + y = 2(x+y)

44 + y = 2x + 2y

44 = 2x + y

44-2x = y

Answer is A.

Kimberly77 · Answer

Hi  BrentGMATPrepNow , is calculation below correct also? Thanks Brent

x = John's PRESENT age
44 = the father's PRESENT age

F=2J
F=2x
44 = 2x
44 - 2x

BrentGMATPrepNow · Answer

Although your calculations are incorrect, you were able to reach the correct answer coincidentally. 
We aren't told the father is PRESENTLY twice as old as his son. 
However, your solution suggests that the father IS presently twice as old as his son, because you have concluded that 44 = 2x, where 44 and x are the father's and son's ages respectively.

steckcha · Answer

Let n be the no. of years after which John’s father will be twice as old as John at that time. 
44 + n = 2(x + n)
44 + n = 2x + 2n
44 - 2x = n
Answer: A.

Posted from my mobile device

Kimberly77 · Answer

Understand now. Thanks BrentGMATPrepNow the great clarification

AdarshSambare · Answer

GIVEN:
x = John’s present age
Father’s present age = 44

Let k = the number of years until the father is twice as old as John.

Then:

* John’s age in k years = x + k
* Father’s age in k years = 44 + k

Condition:
44 + k = 2(x + k)

Expand:
44 + k = 2x + 2k
44 = 2x + k
k = 44 − 2x

So, in 44 − 2x years, the father will be twice John’s age.

Answer: A

If John is x years old now, and his father is 44 years old now, in how

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If John is x years old now, and his father is 44 years old now, in how

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