A and B can do a job together in 7 days. A is 1 3/4 times as efficient as B. The same job can be done by A alone in :

• Ratio of work done by A and B = 7/4 : 1 = 7:4
  
  (A+B)'s 1 day's work = 1/7 (Given in the problem)
  Divide 1/7 in the ratio 7:4
  A's 1 day's work = (1/7 * 7/11)= 1/11
  Hence,A alone can finish the work in 11 days.
  
  B's 1 day's work = (1/7 * 4/11)=4/77 = 1/19.25
  Hence,B alone can finish the work in 19.25 days.
• 10 years agoHelpfull: Yes(5) No(2)
• 
  A:B=1:(7/4) = 4:7
  let B=7x, A=4x
  1/(7x) + 1/(4x) = 1/7
  x= 77/28
  A= 4 x 77/28 = 11 days
  B= 19 x 77/28 = 19.2 days
  your feedback is valuable to me
  
• 11 years agoHelpfull: Yes(4) No(7)
• (A's 1 day's work) : (B's 1 day's work) = 7 : 1 = 7 : 4.
  4
  Let A's and B's 1 day's work be 7x and 4x respectively.
  
  Then, 7x + 4x = 1 11x = 1 x = 1 .
  7 7 77
  A's 1 day's work = 1 x 7 = 1 .
  77 11
  
• 11 years agoHelpfull: Yes(0) No(0)
• but how are you making a:b 7/4 : 1 to 7:4 please explain
• 10 years agoHelpfull: Yes(0) No(0)
• 7/4:1 to make it whole number multiply by 4 on both sides (4 is the denominator) so 7:4.
  for example 2/5:6 is equal to multiply by denominator 5 gives 2/5*5=2 6*5=30. so ratio is 2:30
• 6 years agoHelpfull: Yes(0) No(0)