cant find what is wrong

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by lachlanc » Fri Sep 12, 2008 11:51 am
Yes.

Your problem is that you are not reading the question thoroughly. It is not 1/4 of the total distance, but rather 1/4 of the distance remaining.

If she drives half the distance, then 1/4 of the remaining half, she has travelled 5/8 of the total distance. The remaining 3/8 = 120. Solve for total distance -

120/3 * 8 = 320

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by cramya » Mon Sep 15, 2008 9:17 pm
Let x miles be the total distance.

Maria stopped after travelling half the distance i.e. x/2 miles

Thene she stopped after travelling 1/4th of the remaining distance(Since Maria has travelled x/2 miles already the remaining would be
x-x/2) and 1/4 the of that is 1/4(x-x/2). Then she travels 120 miles.

There x/2 + 1/4(x-x/2)+120 = x

Solving for x we get x = 320

Check:

320/2 = 160 Remaining distance = 1/4(320-160) = 40 Then 120

160+40+120 = 320

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by cramya » Mon Sep 15, 2008 9:19 pm
Let x miles be the total distance.

Maria stopped after travelling half the distance i.e. x/2 miles

Then she stopped after travelling 1/4th of the remaining distance.Since Maria has travelled x/2 miles already the remaining would be
x-x/2 and 1/4 th of that is 1/4(x-x/2).

Then she travels 120 miles.

Therefore all 3 above put together must be equal to the total destination miles

i.e.

x/2 + 1/4(x-x/2)+120 = x

Solving for x we get x = 320

Check:
320/2 = 160 Remaining distance = 1/4(320-160) = 40 Then 120

160+40+120 = 320

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by niraj_a » Tue Sep 16, 2008 8:41 am
i solved this using backsolving, fairly easy, but easy to lose track of what they are really asking for, when doing the calculations.

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by kris610 » Tue Sep 16, 2008 8:42 am
Is it a GMATPrep question? If so, please state that explicitly in the topic. I'm sorry if it is not.

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DRAW

by robzoc » Wed Sep 17, 2008 1:45 pm
what i try doing for questions like these is drawing a line and
marking point along, of course following the questions instructions !!

"not draw to scale nor .. nor even close.. but you can have an idea...

l--------------l----l----l----l----l
1st half l l
here she stops
l
l here is 1/4 of the remaing distance...

so... you have left 3/4 wich accounts for 120 miles...

3/4=120 miles
1/4= 40miles

half of the trip is 160 miles

160 x 2 = 320 the total distance !!!