General Simplification Strategy..

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General Simplification Strategy..

by shayam » Mon Oct 17, 2011 8:48 am
Hey All,
This might sound really really trivial.. :)
While I work on problems that involve Fraction,Decimal/Percent manipulation, I observed that , If I use decimal rather than fraction conversions,I reach answer faster.. and in some cases using fractions instead of decimal conversion form gets me to the answer faster.

As an instance,mgmat practice problem :

Stacy and Heather are 20 miles apart and walk towards each other along same route.
Stacy walks at a constant rate that is 1 mile per hour faster than heather's constant
rate of 5 miles/hour. If Heather starts her journey 24 minutes after Stacey, How far
from her original destination has Heather walked when the two meet?

When I convert min to hour.. I express it as 24/60 or 6/15 instead of using 0.4
Hence instead of manipulating equation as 11t + 2.4 = 2O,I use 11t + 36/15=20

I am more inclined to express values as fractions and I have faced this problem many times.Though its matter of seconds here,I still need to understand this basic question..and how masters out here think......

Thanks a lot..
Source: — Problem Solving |

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by tpr-becky » Mon Oct 17, 2011 3:26 pm
I think it is generally better to use fractions - there are some problems that may work out better with decimals, however fractions allow for easier factoring and it is more clear if you happen to make a mathmatical mistake. The only time I personally woudl use decimals is when the decimal is easy to figure out and the answers are in decimals.
Becky
Master GMAT Instructor
The Princeton Review
Irvine, CA