og math ps #140 math translations

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og math ps #140 math translations

by resilient » Wed Feb 13, 2008 2:40 pm
Jack is now 14 years older than Bill. If in 10 years JAck will be twice as old as Bill, how old will JAck be in 5 years?

a. 9
b.19
c.21
d.23
e.33

I am having trouble taking this from plain English to two different equations. ANy help

I got (j +14=b) and (2j +10 =b = 10)

must solve for j +5= i came to an answer of 19.








qa is D
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by its_me07 » Thu Feb 14, 2008 4:03 am
Jack is now 14 yrs older than Bill
j=b+14

in 10 yrs
j+10=2(b+10)
so
b=4 that means j=18 and in 5 years he will be 23 .Hence D.

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by bpgen » Fri Mar 05, 2010 8:39 pm
Just wondering, what does it mean by 'If in 10 years Jack will be twice as old as Bill' ? I mean, what is it indicating ? 'as old as Bill' IS/WILL BE ?, if we consider Bill 'IS', then equation might be changed to J+10=2b, Correct me what to consider, 'IS' or 'WILL BE'? Appreciate help.
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by papgust » Fri Mar 05, 2010 9:14 pm
'If in 10 years Jack will be twice as old as Bill' means that after 10 years from now, jack will be twice as old as Bill.

The equation will be (J+10) = 2(B+10). Because, even Bill will be +10 years old after 10 years from now. I don't understand your doubt reg is/will be.

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by bpgen » Sat Mar 06, 2010 7:33 am
Thanks papgust!, what I'm saying whether actual question "Jack is now 14 years older than Bill. If in 10 years JAck will be twice as old as Bill, how old will JAck be in 5 years? " is meaning as:

Jack is now 14 years older than Bill. If in 10 years JAck will be twice as old as Bill [spoiler]is of now[/spoiler], how old will JAck be in 5 years?

or

Jack is now 14 years older than Bill. If in 10 years JAck will be twice as old as Bill will be, how old will JAck be in 5 years?

I know it's very simple thing, but exploring all those meaning, if they really could make any sense!
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by papgust » Sat Mar 06, 2010 8:43 am
Ok. Now i get it. It should be the second one.

"is of now" implies Bill's current age and not the age 10 years from now. Question clearly says that "If in 10 years JAck will be twice as old as Bill". The 10 years calculation includes both Jack and Bill.

Hope i've answered your query.

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by bpgen » Sat Mar 06, 2010 9:42 am
Thanks papgust for your clarification!
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by dumluck » Wed May 04, 2011 4:16 am
Hi All,
Could anyone show me how to solve this using a chart, i.e. The MGMAT way?

Thanks,
D

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by GMATGuruNY » Wed May 04, 2011 6:21 am
Jack is now 14 years older than Bill. If in 10 years JAck will be twice as old as Bill, how old will JAck be in 5 years?

a. 9
b.19
c.21
d.23
e.33
We can plug in the answers, which represent Jack's age in 5 years.

Answer choice C: Jack in 5 years = 21.
Jack's current age = 21-5 = 16.
Bill's current age = 16-14 = 2.
Jack in 10 years = 16+10 = 26.
Bill in 10 years = 2+10 = 12.
Jack's age is not twice Bill's age.
Eliminate C.
Since the smaller answer choices will make Bill's age 0 or less, eliminate A and B.

Answer choice D: Jack in 5 years = 23.
Jack's current age = 23-5 = 18.
Bill's current age = 18-14 = 4.
Jack in 10 years = 18+10 = 28.
Bill in 10 years = 4+10 = 14.
Success! Jack's age is twice Bill's age.

The correct answer is D.
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by dumluck » Wed May 04, 2011 6:45 am
Thanks for the response... is their a table method for this though?

NOW || 5 YEARS || 10 YEARS ||
Bill J - 14 || J - 9 || J + 10/2||
Jack J || J + 5? || J + 10 ||
TOTAL 2J - 14 || 2J - 4 || 3J + 3 ||

Something along those lines?