YTT wrote:
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 * 5 * 5. How many two-digit positive integers have length 6?
A. None
B. One
C. Two
D. Three
E. Four
Lets start with smallest prime number\(2\).
\(2^6 = 64\) ---------- (Length\(= 6\))
\(2^7\) is three digit number hence cannot be\(n\) .
Therefore lets move to next prime number\(3\) .
\(2^5*3^1 = 32*3 = 96\) ---------- (Length\(= 6\) )
\(2^4*3^2\) will be three digit
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