jade3 wrote:
For how many values of k is 12^12 the least common multiple of the positive integers 6^6, 8^8 and k?
A. 23
B. 24
C. 25
D. 26
E. 27
6^6 = (2^6)*(3^6)8^8 = 2^{24}Now we know that the least common multiple of the above two numbers and k is:
12^{12} = (2*2*3)^{12} = (2^{24})*(3^{12})Thus, k will also be in the form of :
(2^a)*(3^b)Now, b has to be equal to 12 since in order for
(2^{24})*(3^{12}) to be a common multiple, at least one of the numbers must have the terms
2^{24} and
3^{12} as its factors. (not necessarily the same number).
We can see that
8^8 already takes care of the
2^{24} part.
Thus, k has to take care of the
3^{12} part of the LCM.
This means that the value k is
(2^a)*(3^{12}) where a can be any value from 0 to 24 (both inclusive) without changing the value of the LCM.
Thus K can have 25 values. Choice (c).
Cheers.