How many ways can 840 be written as the product of two numbers ?
a) 32
b) 16
c) 6
d) 18

• Factors are (2,2,2,3,5,7)
  i.e 2^3*3*5*7
  now total add 1 to the powers and multiply(general rule of finding divisor)
  i.e (3+1)*(1+1)*(1+1)*(1+1)=32
• 10 years agoHelpfull: Yes(21) No(3)
• factors of 840 : 2,2,2,3,5,7.
  sets :: {2,4,3,5,7}
  total number of elements it has 2^5 =32
  
• 10 years agoHelpfull: Yes(17) No(3)
• b) 16
  
  It is equal to half of the number of factors of 840
  840 = 2^3 * 3 * 5 * 7 => 32 factors
  
  => 32/2 = 16 ways
• 10 years agoHelpfull: Yes(14) No(11)
• The correct answer is 16.
  The way to find number of factors is....convert the given number to the product of prime factors by taking LCM.
  840=2*2*2*3*5*7=2^3 * 3^1 * 5^1 * 7^1
  no.of factors=(3+1)*(1+1)*(1+1)*(1+1) = 32.
  the no.of ways expressing as a product of two terms is = 32/2 = 16.
• 8 years agoHelpfull: Yes(5) No(0)
• plssssssssss explain this ans
• 10 years agoHelpfull: Yes(1) No(0)
• 840= 2^3*5^1*21^1
  no.of factors= (3+1)(1+1)(1+1)= 16
• 10 years agoHelpfull: Yes(1) No(4)
• 16 is correct
• 10 years agoHelpfull: Yes(1) No(2)
• ans is :32
• 10 years agoHelpfull: Yes(0) No(0)
• why powers are added
• 10 years agoHelpfull: Yes(0) No(0)
• total factors/2
  b)
• 10 years agoHelpfull: Yes(0) No(1)
• mr. kunal u'r eplanation is right but que is asking abt pair so they should be half
  for instance 18 it have 2*3^2means 2+4 factors ie. 1 2 3 6 9 & 18 but we want to pair hence thr is only 3 pair
  hence
• 10 years agoHelpfull: Yes(0) No(0)
• plz send correct ans is it 32 or 16 ??
• 10 years agoHelpfull: Yes(0) No(2)