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(3^x) (4^y) (5^z) = 3,276,800,000

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(3^x) (4^y) (5^z) = 3,276,800,000

by sanju09 » Mon Feb 21, 2011 1:01 am
For integers x, y, and z, if (3^x) (4^y) (5^z) = 3,276,800,000 and x + y + z = 15, what is the value of xy/z?
(A) undefined
(B) 0
(C) 3
(D) 5
(E) 15
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by rohu27 » Mon Feb 21, 2011 1:13 am
B

the given number is not a multiple of 3. so x must be zero.
i guess this is one of those questioswhere extra info is given.

sanju09 wrote:For integers x, y, and z, if (3^x) (4^y) (5^z) = 3,276,800,000 and x + y + z = 15, what is the value of xy/z?
(A) undefined
(B) 0
(C) 3
(D) 5
(E) 15
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by BarryLi » Mon Feb 21, 2011 1:20 am
In addition to x being zero, I believe it should be confirmed that z != 0. This is done by working out by hand 4^y for some integer close to 32,768. This is because 32,768 is a power of 2.
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by manpsingh87 » Mon Feb 21, 2011 1:20 am
sanju09 wrote:For integers x, y, and z, if (3^x) (4^y) (5^z) = 3,276,800,000 and x + y + z = 15, what is the value of xy/z?
(A) undefined
(B) 0
(C) 3
(D) 5
(E) 15
B
as the given number is not divisible by 3..!!!
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by rohu27 » Mon Feb 21, 2011 1:27 am
guess thts implied. as we have zeros at the end. despite the fact tht 32768 is factor of 4, the zeros bring 5 into euation.

BarryLi wrote:In addition to x being zero, I believe it should be confirmed that z != 0. This is done by working out by hand 4^y for some integer close to 32,768. This is because 32,768 is a power of 2.
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