B is twice as fast as A and C is twice as fast as B. If A alone can complete the job in 24 days, how many days will A, B and C take to complete the job working together?

• 4 days
  
  B is twice as fast as A and C is twice as fast as B.
  If C takes x days to complete the job alone,
  B will take 2x days and A will take 4x days.
  If A alone can complete the job in 24 days,
  so 4x = 24
  x= 6
  so C will take 6 days and B will take 12 days when working alone.
  One day work of B and C together = 1/6 + 1/12 = 3/12 = 1/4
  when B and C work together, they will take 4 days.
• 12 years agoHelpfull: Yes(1) No(0)
• 4 days
  
  B is twice as fast as A and C is twice as fast as B.
  If C takes x days to complete the job alone,
  B will take 2x days and A will take 4x days.
  If A alone can complete the job in 24 days,
  so 4x = 24
  x= 6
  so C will take 6 days and B will take 12 days when working alone.
  
  when B and C work together, they will take 1/(1/6+1/12) = 12/3= 4 days.
• 12 years agoHelpfull: Yes(0) No(0)
• 24/7 Days
  A's 1 day job=1/24
  B's 1 day job=2/24=1/12
  C's 1 day job=4/24=1/6
  If A,B & C works together,their 1 day job=1/24+1/12+1/6=7/24
  Therefore days to complete the job if A,B & C works together=24/7
  
• 12 years agoHelpfull: Yes(0) No(0)