30-23

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by beny » Sat Aug 25, 2007 2:54 pm
Realize that .8 = 8/10 = 4/5
.4 = 4/10 = 2/5

.08^-5 = 1/(4/5)^5 = (5/4)^5

.04^-4 = 1/(2/5)^4 = (5/2)^4

We want to solve for:
(5/4)^5/(5/2)^4

(5^5/4^5)/(5^4/2^4)
=(5^5/2^10)/(5^4)/(2^4)
=(5^5*2^4)/(5^4*2^10)
=5/2^6
=5/64

Answer B.

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by magical cook » Sun Aug 26, 2007 5:04 pm
Thant's correct - thanks!