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by akane » Sat Nov 05, 2011 8:15 am
Does anyone know a way to solve questions like what is the value of 2^5+2^5+3^5+3^5+3^5 I keep seeing that in the GMAT testprep.I would like to know if there is an (efficient)method for tackling these kind of questions.Thanks for your posts.
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by vaibhavgupta » Sat Nov 05, 2011 9:25 am
akane wrote:Does anyone know a way to solve questions like what is the value of 2^5+2^5+3^5+3^5+3^5 I keep seeing that in the GMAT testprep.I would like to know if there is an (efficient)method for tackling these kind of questions.Thanks for your posts.
it will come down to 2^6+3^5*2

which = 64+ 486
= 550

could u explain a bit more about wht u want strategies on?
If OA is A, IMO B
If OA is B, IMO C
If OA is C, IMO D
If OA is D, IMO E
If OA is E, IMO A

FML!! :/
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by GmatMathPro » Sat Nov 05, 2011 9:48 am
akane wrote:Does anyone know a way to solve questions like what is the value of 2^5+2^5+3^5+3^5+3^5 I keep seeing that in the GMAT testprep.I would like to know if there is an (efficient)method for tackling these kind of questions.Thanks for your posts.
Let x=2^5, let y=3^5

The expression becomes x+x+y+y+y=2x+3y=2*2^5+3*3^5=

2^6+3^6=64+729=793.

At the end, if you don't know the values of 2^6 or 3^6 off the top of your head, the best you can do is rewrite them: 2^6=(2^3)^2=8^2=64. 3^6=(3^2)^3=9^3=81*9=729.

Depending on the answer choices you may be able to get the answer just based on the unit's digit and not have to calculate it completely.
Pete Ackley
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by vaibhavgupta » Sat Nov 05, 2011 9:50 am
GmatMathPro wrote:
akane wrote:Does anyone know a way to solve questions like what is the value of 2^5+2^5+3^5+3^5+3^5 I keep seeing that in the GMAT testprep.I would like to know if there is an (efficient)method for tackling these kind of questions.Thanks for your posts.
Let x=2^5, let y=3^5

The expression becomes x+x+y+y+y=2x+3y=2*2^5+3*3^5=

2^6+3^6=64+729=793.

At the end, if you don't know the values of 2^6 or 3^6 off the top of your head, the best you can do is rewrite them: 2^6=(2^3)^2=8^2=64. 3^6=(3^2)^3=9^3=81*9=729.
Think u did a mistake there..

3^5+3^5 is not equal to 3^6
3^5 common (1+1)
2*3^5

:)
If OA is A, IMO B
If OA is B, IMO C
If OA is C, IMO D
If OA is D, IMO E
If OA is E, IMO A

FML!! :/
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by vaibhavgupta » Sat Nov 05, 2011 9:51 am
vaibhavgupta wrote:
GmatMathPro wrote:
akane wrote:Does anyone know a way to solve questions like what is the value of 2^5+2^5+3^5+3^5+3^5 I keep seeing that in the GMAT testprep.I would like to know if there is an (efficient)method for tackling these kind of questions.Thanks for your posts.
Let x=2^5, let y=3^5

The expression becomes x+x+y+y+y=2x+3y=2*2^5+3*3^5=

2^6+3^6=64+729=793.

At the end, if you don't know the values of 2^6 or 3^6 off the top of your head, the best you can do is rewrite them: 2^6=(2^3)^2=8^2=64. 3^6=(3^2)^3=9^3=81*9=729.
Think u did a mistake there..

3^5+3^5 is not equal to 3^6
3^5 common (1+1)
2*3^5

:)
oHh... i did not see there are 3 of them

my bad !:) sorry
If OA is A, IMO B
If OA is B, IMO C
If OA is C, IMO D
If OA is D, IMO E
If OA is E, IMO A

FML!! :/
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