A can finish a work in 24 days, B in 9 days and C in 12 days. B and C start the work but are forced to leave after 3 days. The remaining work was done by A in:

• A's 1 day work:1/24
  B's1 day work:1/9
  C's 1 day work:1/12
  (B+C)1day work:1/9+1/12=7/36
  (B+C)3 days work=7*3/36=7/12
  remaining work=1-7/12=5/12
  5/12work is done by A in 5/12*24=10days
• 12 years agoHelpfull: Yes(8) No(0)
• mohd zubair khan, i unable to understand that why you have divided by 12 at last line please explain.
  
• 12 years agoHelpfull: Yes(1) No(0)
• A's 1 day work = 100/24 = 4.16 %
  B's 1 day work = 100/9 = 11.11 %
  C's 1 day work = 100/12 = 8.33 %
  B+C's 1 day work =11.11 + 8.33 = 19.44 %
  B+C's 3 day work = 19.44 x 3 = 58.32 %
  remaining work=100-58.32 = 41.68
  41.68 % work completed by A = 41.68/12 = 3.14 days (ans)
  
• 12 years agoHelpfull: Yes(0) No(6)