How many nos from 1 to 100 have prime no of factors?
i)25,ii)29,iii)32,iv)33

• Answer is 32.
  As per the Question we should find out the nos which have no of factors=prime no(the factors may be prime or not)
  There are 25 prime nos which have only 2(Prime) factors.
  And the squares :4,9,16,25,49,64,81 have also prime no of factors.
  So total=25+7=32
• 11 years agoHelpfull: Yes(41) No(12)
• Answer is 33
  As we know the total no. of Prime numbers between 1 and 100 are 25 and they have only two numbers as their factors.
  and there are squares like 4,9,16,25,49,64,81 and also 100 is included because in the question it is given as 1 to 100 but not as in between 1 to 100
  so total 25+8=33
• 11 years agoHelpfull: Yes(13) No(12)
• 16 has factors 1,2,4,8,16=5 no of factors and 5 is a prime no.You can check others also.
• 11 years agoHelpfull: Yes(6) No(3)
• Answer is 25
  Because Prime nos b/w 1-100 is 25 and questions says that factors of prime no is prime so only prime nos considered b/w 1-100.
• 11 years agoHelpfull: Yes(5) No(5)
• total 25 ...2,3,5,7,11,13,17,19,23,29,31,37,41,43,47,53,59,61,67,71,73,79,83,89,97.
• 11 years agoHelpfull: Yes(4) No(3)
• 33
  there a 25 prime numbers less than 100 and 8 squares less than 100 with prime factors
  25+7
• 11 years agoHelpfull: Yes(3) No(2)
• 16,64,81 numbers having multiple factors..ans is 29
• 11 years agoHelpfull: Yes(2) No(8)
• as we know the no of prime num between 1 to 100 is 25.
  we also know the formula to find no of factors.
  is if no of the format 2^x*3^y.
  then no of factors is (x+1)(y+1).
  like wise if we need to find the num with prime factors we need to verify for prime powers 2,3,5,7.
  for case 2-->2^n such that (n+1) is prime.it n needs to be 1,2,4,6.thus we get 4,16,64
  for case 3 we get 9,81
  for case 5 we get 25
  for case 7 we get 49
  total 25+7=33 values
  
• 8 years agoHelpfull: Yes(2) No(1)
• sry 27+8=33
• 11 years agoHelpfull: Yes(1) No(3)
• 33 is the ans.
• 8 years agoHelpfull: Yes(1) No(6)
• 25 prime numbers are there
• 7 years agoHelpfull: Yes(1) No(0)
• i think @MAHESH GUNTUMADUGU is right
• 7 years agoHelpfull: Yes(0) No(1)
• 33 is right ans
• 7 years agoHelpfull: Yes(0) No(3)
• 25 primes and (4,9,16,25,49,64,81) = total 32 ans
• 1 year agoHelpfull: Yes(0) No(0)