What is the number of odd factors of 49000000?
Ans.21

• For these types of questions:
  First resolve given number into powers of prime factors(i.e 2*2*5**5.....)
  Then:
  to find number of even factors: ignore 2^0 and find product of (prime factor's powers+1)
  to find number of odd factors: ignore all 2 powers except 2^0 and find product of (prime factor's power+1)
  
  for 49000000= 7^2*2^6*5^6
  ignore all 2powers except 2^0 i.e now 7^2*2^0*5^6
  num of factors (as said above)= (2+1)(0+1)(6+1)=7*1*3=21
• 10 years agoHelpfull: Yes(43) No(0)
• 49000000 factors are 7^2 * 5^6 * 2^6
  we need only odd factors
  so only consider 7 & 5 combinations
  is (2+1)*(6+1) = 21
  (short cut of finding factor of any combination)
• 10 years agoHelpfull: Yes(5) No(0)
• the factors of 49000000 is 7^2*5^6*2^6
  so to have odd factors the ans would be given as
  (2+1(6+1)=21
  bcz to hav odd factors odd*odd=odd
  therefore 2^6 is neglected
• 10 years agoHelpfull: Yes(2) No(0)
• 49000000=7^2*2^6*5^6
  total number of factors=(2+1)*(6+1)*(6+1)=7*7*3
  now total number of even factors=6(occurance of 2)*(2+1)*(6+1);
  hence odd factors=7*7*3-6*3*7=7*3(7-6)=21 ans.
• 10 years agoHelpfull: Yes(1) No(0)
• 49000000
  49*1000000
  7^2*10^6
  (2+1)*(6+1)=21
• 10 years agoHelpfull: Yes(1) No(0)
• I think ans will be 20
  49000000=7*7*2*5*2*5*2*5*2*5*2*5*2*5
  
  so odd factors are
  5
  5*5
  5*5*5
  5*5*5*5
  5*5*5*5*5
  5*5*5*5*5*5
  5*7
  5*5*7
  5*5*5*7
  5*5*5*5*7
  5*5*5*5*5*7
  5*5*5*5*5*5*7
  5*7*7
  5*5*7*7
  5*5*5*7*7
  5*5*5*5*7*7
  5*5*5*5*5*7*7
  5*5*5*5*5*5*7*7
  7
  7*7
• 10 years agoHelpfull: Yes(0) No(9)