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PS - exponent

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PS - exponent

by Xbond » Sun Jul 06, 2008 8:14 am
Hi there,

Could you explain to me how you resolve this PS ,

if (1/5)^m (1/4)^18 = 1/2(10)^35, then m=

A. 17
B. 18
C. 34
D. 35
E. 36

I select A but it's wrong

Could help me

Xbond
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by rs2010 » Sun Jul 06, 2008 9:09 am
Compare the exponent power.

I am confused with the RHS part of your problem, so cant say anything abt it. But you can perform operation like

(1/5)^m * (1/2)^36 = (1/2) * (2*5)^35

which will be

1=5^(m+35) * 2^ 70
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by tejam800 » Sun Jul 06, 2008 9:46 am
if the q is

(1/5)^m * (1\4)^18 = (1/(2*(10^35))

i got m = 35

(1/5)^m * (1\2)^36 = (1/2)^36 * (1/(5^35))
(1/5)^m = (1/5)^35

plz som 1 validate this
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by rs2010 » Sun Jul 06, 2008 10:04 am
This is correct if you assume 10 in DR.
And thats what i wrote earlier.
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by sibbineni » Sun Jul 06, 2008 11:20 am
Question

(1/5)^m (1/4)^18 = 1/2(10)^35

Left hand side

(1/5)^m (1/4)^18 ==>5^-m 2^-36

Right hand side

1/2(10)^35===>1/2^36*5^35==>2^-36 5^-35

lhs=rhs


5^-m 2^-36=2^-36 5^-35

equating whose bases are equal then

-m=-35

m=35
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by Xbond » Sun Jul 06, 2008 1:15 pm
many thks
the answer was D
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