prime

Guest · Posted: Fri Oct 12, 2007 1:03 pm Post subject: prime

positive integer n is called prime sat if product of all different positive prime factors of n is less than sqrt of n. which of the following is prime sat

18
25
56
96
120

Suyog · Posted: Fri Oct 12, 2007 9:54 pm Post subject:

18 = 3*3*2
Product of prime factors 6
root 18 is approx 4.2 ..NO

25 = 5*5
Product of prime factors 5
root 25 is 5 ..NO

56 = 7*2*2*2
Product of prime factors 14
root 56 is approx 7.3 ..NO

96 = 3*2*2*2*2*2
Product of prime factors 6
root 96 is approx 9.8 ..YES

120 = 5*3*2*2*2
Product of prime factors 30
root 120 is approx 11 ..NO

Ans D.