how many natural numbers are only factors of 720 and 840

pleasse give the approach

1) 30
2) 46
3) 60
4) 32

• 720 =2^4*3^2*5
  no of divisors=5*3*2=30
  840=2^3*3*5*7
  no of divisors=(3+1)*(1+1)*(1+1)*(1+1)=4*2*2*2=32
  720 and 840=30+32=62
• 11 years agoHelpfull: Yes(0) No(0)