For any positive integer n, the length of n is defined as the number of prime factors whose product is n. For example, the length of 75 is 3, since 75 = 3 x5x5. How many two digit positive integers have length 6?
A)None
B)One
C)Two
D)Three
E)Four
2*2*2*2*2*2
2*2*2*2*2*3
2*2*2*2*3*1
2*2*2*2*2*1......这么往下多了去了 这题问题出在哪里??
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