BREAKING: Target Test Prep releases Brand New 2026 On Demand GMAT prep course

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by Naruto » Wed Jul 22, 2009 4:08 am
Detailed explanation please.

OA E

Am sorry had attached the wrong file :)
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Last edited by Naruto on Wed Jul 22, 2009 4:21 am, edited 2 times in total.
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by tohellandback » Wed Jul 22, 2009 4:15 am
from the image,
4+y=-5
y=-9

4+x=1
x=-3

e+x=7
or,e+(-3)=7
e=10

e+z=10
z=10-e=10=10=0

n=e+y
=10-9=1

m=4+z=4+0=4

so m+n=4+1=5
The powers of two are bloody impolite!!
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by sreak1089 » Wed Jul 22, 2009 4:49 am
You can have one-letter, two-letter and three-letter codes:

1) one-letter codes: 26 possibilities
2) two-letter codes: 26 * 26 possibilities (since repetion is allowed)
3) three-letter codes: 26 * 26 * 26 possibilities

Total no of possibilities = 26 + 26 * 26 + 26 * 26 * 26 = 18278
Hence answer is E
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by PussInBoots » Sat Jul 25, 2009 5:16 pm
Would not it take a significant time to calculate 26 + 26^2 + 26^3?
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by prindaroy » Sat Jul 25, 2009 7:34 pm
well the only calculation you would actually have to do is 26^3. 26^2 is simply 625 + 25 + 26 = 676. If you remember that 25^2 = 625. Also, 625 * 26 should take less than a minute for sure.
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by sreak1089 » Sat Jul 25, 2009 8:04 pm
Only calculation you have to do is 676 * 26. It helps if you remember squares of numbers up to 35.
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