There are four prime numbers written in ascending order of magnitude. The product of first three is 385 and that of last three is 1001. Find the first number.
Option 1 : 5 Option 2 : 7 Option 3 : 11 Option 4 : 17

• let four prime number wriiten in ascending order be x,y,z and p
  now according to question ,
  product of first three number
  x*y*z=385
  y*z=385/x
  product of last three number
  p*y*z=1001
  p*385/x=1001
  p/x=1001/385
  p/x= 13/5
  x=5
  option 1: 5 is correct answer
• 10 years agoHelpfull: Yes(9) No(1)
• LET THE 4 PRIME NO'S BE a,b,c,d
  product of first 3 no's => abc=385
  product of last 3 no's => bcd=1001
  now, abc/bcd=>385/1001
  a/d=>5/13
  hence the first no. is a=5
• 9 years agoHelpfull: Yes(3) No(0)
• first we find prime factorization of 385
  385=5*7*11
  same 1001=7*11*13
  all prime no:5,7,11,13
  ans:5
  
• 10 years agoHelpfull: Yes(2) No(1)
• 5 Since 385 is divisible by 5,7,11 and 1001 is divisible by 7,11,13 so its 5
  
• 10 years agoHelpfull: Yes(1) No(0)