Age?

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Age?

by brick2009 » Tue Nov 10, 2009 8:15 pm
Q9:How many years did Dr. Jones live?
(1) If Dr. Jones had become a doctor 10 years earlier than he did, he would have been a
doctor for exactly 2/3 of his life.
(2) If Dr. Jones had become a doctor 10 years later than he did, he would have been a doctor
for exactly 1/3 of his life.


OA: C

How????

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by anandr84 » Tue Nov 10, 2009 10:55 pm
D= no of years jones was a doc
T= total number of years he lived

1> D+10 = (2/3)T
INSUFFICIENT

2> D-10 = (1/3)T
INSUFFICIENT

1 & 2> Solving the simultaenuous equations we can get T

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by brick2009 » Tue Nov 10, 2009 11:15 pm
;) ..even i had arrived at that equation..but when you go ahead and solve it...you get 2D = T.

i think the answer is wrong>>>>

anandr84 wrote:D= no of years jones was a doc
T= total number of years he lived

1> D+10 = (2/3)T
INSUFFICIENT

2> D-10 = (1/3)T
INSUFFICIENT

1 & 2> Solving the simultaenuous equations we can get T

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by jaspreet_takhar » Wed Nov 11, 2009 1:03 am
brick2009 wrote:;) ..even i had arrived at that equation..but when you go ahead and solve it...you get 2D = T.

i think the answer is wrong>>>>

anandr84 wrote:D= no of years jones was a doc
T= total number of years he lived

1> D+10 = (2/3)T
INSUFFICIENT

2> D-10 = (1/3)T
INSUFFICIENT

1 & 2> Solving the simultaenuous equations we can get T
Subtract Eq 2 from eq 1,u'll get T = 60

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by brick2009 » Wed Nov 11, 2009 7:09 am
awwww.. true...
this is just great..weeks before the exam.. i forget the fundamentals..;-)


jaspreet_takhar wrote:
brick2009 wrote:;) ..even i had arrived at that equation..but when you go ahead and solve it...you get 2D = T.

i think the answer is wrong>>>>

anandr84 wrote:D= no of years jones was a doc
T= total number of years he lived

1> D+10 = (2/3)T
INSUFFICIENT

2> D-10 = (1/3)T
INSUFFICIENT

1 & 2> Solving the simultaenuous equations we can get T
Subtract Eq 2 from eq 1,u'll get T = 60

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hmm

by JeffB » Wed Nov 11, 2009 9:28 am
I wouldn't have even wasted my time trying to solve for T. You have (2) equations and (2) unknowns.

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by grockit_jake » Fri Nov 13, 2009 2:30 pm
yes, no need to plug in and solve on data sufficiency questions.

If there are 2 linear eqs and 2 unknowns (that are not identical multiples of each other) then you have a unique solution.
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