Question 353100: The number 2^48 - 1 divisible by two numbers between 60 and 70. Their sum is:
(a) 124 (b) 128 (c) 132 (d) 136 (e) None of the above
Answer by CharlesG2(834)   (Show Source):
You can put this solution on YOUR website! The number 2^48 - 1 divisible by two numbers between 60 and 70. Their sum is:
(a) 124 (b) 128 (c) 132 (d) 136 (e) None of the above
http://www.wolframalpha.com/input/?i=factor+%282%5E48%29-1
(used factor 2^48 - 1 to get factors)
prime factorization: 3^2 * 5 * 7 * 13 * 17 * 97 * 241 * 257 * 673
this gives 768 divisors according to wolframalpha
here is the ones up to 105:
1,3,5,7,9,13,15,17,21,35,39,45,51,63,65,85,91,97,105
the 2 numbers between 60 and 70 are 63 and 65
63 + 65 = 128, answer is (b) 128
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