For how many positive integers x is 130/x an integer?
a) 8 b) 7 c) 6 d) 5 e) 3
i dont have the OA. My answer is a, would like to confirm.
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Number properties PS
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grockit_jake
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Yes, you are correct. You can first break 130 into its factors, and then recombine to see how many fit.
130 = 2*65 = 2*5*13
2, 5, 13, 10, 65, 26, 130, 1.
Count your way up, and when you hit the max, you know you are done.
130 = 2*65 = 2*5*13
2, 5, 13, 10, 65, 26, 130, 1.
Count your way up, and when you hit the max, you know you are done.
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punitkaur
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thanks for confirming. but the way i did it was a little different.
130
prime factors - 2,5,13.
no of divisors is multiplication of (powers of each +1)
2x2x2 = 8.
If we got a larger number then this method is easier I believe?
130
prime factors - 2,5,13.
no of divisors is multiplication of (powers of each +1)
2x2x2 = 8.
If we got a larger number then this method is easier I believe?
-
tohellandback
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I think your method is better than one stated above..punitkaur wrote:thanks for confirming. but the way i did it was a little different.
130
prime factors - 2,5,13.
no of divisors is multiplication of (powers of each +1)
2x2x2 = 8.
If we got a larger number then this method is easier I believe?
the other method can be time-taking if there are large numbers.
The powers of two are bloody impolite!!
