in how many ways can the sum of all the factors of 2160 be written as a product of two factors which are relatively prime?
a)4
b)5
c)7
d)8

• ans:8
  sum of factors of 2160=7440(by using the formula of calculating the sum of factors)
  then 7440=2^4*3*5*31
  ways of writing a number as product of two co prime factors=2^(n-1)
  where n=number of prime factor of a number
  hence 2^(4-1) =8
• 9 years agoHelpfull: Yes(20) No(0)
• ans:7
  sum of factors of 2160=7440
  2160=2^4*3^3*5
  sum of factors=(1+2+4+8+16)(1+3+9+27)(1+5)
  then 7440=2^4*3*5*31 from this we have 7 relatively primes
  
• 9 years agoHelpfull: Yes(2) No(6)
• 2160= 2^4*3^3*5 so total power 4+3+1=8
• 9 years agoHelpfull: Yes(2) No(0)