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dodgeforgmat
- Senior | Next Rank: 100 Posts
- Posts: 35
- Joined: Mon May 23, 2011 8:05 pm
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Brian Galvin posted this on BTG to explain the importance of breaking complex numbers into their prime factors.
While I totally endorse what he has to say, I am not convinced on the answer to the question he used as an example. Here is my attempt to solve the problem and would request for advice.
x is the product of each integer from 1 to 50, inclusive and , where k is an integer . What is the greatest value of k for which y is a factor of x?
(A) 0
(B) 5
(C) 6
(D) 10
(E) 12
X is the product of all intergers from 1 to 50 inclusive.
so X = 50!
y=100^k = 10^(k+2)
Number of zero's in X is quotients of each of (50/5)+(50/25) = 10+2 = 12
hence X is of the form ABCD....X 10^12
hence k+2 = 12
k = 10
Option D.
What am I missing?
While I totally endorse what he has to say, I am not convinced on the answer to the question he used as an example. Here is my attempt to solve the problem and would request for advice.
x is the product of each integer from 1 to 50, inclusive and , where k is an integer . What is the greatest value of k for which y is a factor of x?
(A) 0
(B) 5
(C) 6
(D) 10
(E) 12
X is the product of all intergers from 1 to 50 inclusive.
so X = 50!
y=100^k = 10^(k+2)
Number of zero's in X is quotients of each of (50/5)+(50/25) = 10+2 = 12
hence X is of the form ABCD....X 10^12
hence k+2 = 12
k = 10
Option D.
What am I missing?
