confusing age problem

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confusing age problem

by kishokbabu » Tue Dec 13, 2011 10:28 am
Kenny is 3 times older than Bob. In P years Kenny will be twice older than Bob will be Q years later. If X denotes Kenny's age, Which of the following represents kenny's age compared to Bob's?

a) X + P = 6X (P + Q)
b) 2 (X + P)= 3X +Q
c) (X+P)/2 = (X/3) +P+Q
d) 3(X+P+Q)= 2X
e) 3x = 2(P+Q)
Source: — Problem Solving |

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by neelgandham » Tue Dec 13, 2011 10:42 am
Kenny is 3 times older than Bob. In P years Kenny will be twice older than Bob will be Q years later. If X denotes Kenny's age, Which of the following represents kenny's age compared to Bob's?

If X denotes Kenny's age and if B denoted Bob's age

Kenny is 3 times older than Bob - X = 3B
In P years Kenny will be twice older than Bob will be Q years later => X+P = 2(B+Q)
Implies 3B + P = 2B + 2Q
Implies B = 2Q - P
Kenny's age = X = 3B = 6Q - 3P

a)X + P = 6X (P + Q) - Nopes
b)2 (X + P)= 3X +Q => X = 2P - Q - Nopes
c):mute: _ Don't know
d)3(X+P+Q)= 2X => X = -3(P+Q) - Nopes
e)3X = 2(P+Q) => X = (2/3)(P+Q) - Nopes

The correct answer should be C provided the option reads (X+P)/2 = X/3 + P + Q. and not as mentioned above !
Last edited by neelgandham on Tue Dec 13, 2011 10:55 am, edited 1 time in total.
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by kishokbabu » Tue Dec 13, 2011 10:52 am
The correct answer gvn is (X+P)/2=(X/3)+P+Q, and i am not getting this answer

neelgandham wrote:Kenny is 3 times older than Bob. In P years Kenny will be twice older than Bob will be Q years later. If X denotes Kenny's age, Which of the following represents kenny's age compared to Bob's?

If X denotes Kenny's age and if B denoted Bob's age

Kenny is 3 times older than Bob - X = 3B
In P years Kenny will be twice older than Bob will be Q years later => X+P = 2(B+Q)
Implies 3B + P = 2B + 2Q
Implies B = 2Q - P
Kenny's age = X = 3B = 6Q - 3P

a)X + P = 6X (P + Q) - Nopes
b)2 (X + P)= 3X +Q => X = 2P - Q - Nopes
c):mute: _ Don't know
d)3(X+P+Q)= 2X => X = -3(P+Q) - Nopes
e)3X = 2(P+Q) => X = (2/3)(P+Q) - Nopes

The correct answer should be C provided the option reads (X+P)/2 = X/3 + P + Q. and not as mentioned above !

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by Mdewan » Tue Dec 13, 2011 11:10 am
Ans: c
My understanding:
Kenny (X) is 3 times older than Bob(B)
X=3B....Equation (1)
In P years
Kenny will be (X+P) twice older than Bob (B+P) will be Q years later (B+P+Q)
(X+P)=2(B+P+Q).... Equation (2)
Substitute equation (1) in equation (2)
(X+P)/2 =(X/3)+(P+Q)

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by MakeUrTimeCount » Wed Dec 14, 2011 7:08 am
Ans : C

Same explaination as Mdewan's