Arun and Tarun can do a work in 10 days.After 4 days tarun went to his village.How many days are required to complete the remaining work by Arun alone.Arun can do the work alone in 30 days.

• 18 days.
  
  They together completed 4/10 work in 4 days.
  balance 6/10 work will be completed by Arun alone in 30*6/10 = 18 days.
• 11 years agoHelpfull: Yes(4) No(0)
• In 1 day,Arun can do 1/30th of his work.
  In 1 day,Arun & Tarun can do 1/10th of work.
  so in 4 days=4/10th of work
  
  hence, remaining work=6/10th of work
  
  1/30th of work arun do in 1 Day
  1 30 days
  6/10th " " 30*6/10=18 days
  
• 11 years agoHelpfull: Yes(1) No(1)
• a+t 's 1 day work=1/10
  a+t's 4 day work=4/10
  after 4 day tarun left,so
  remining work is 6/10,so 30*(6/10)
  18 days needed for arun alone to do work
• 11 years agoHelpfull: Yes(1) No(1)
• let arun's one day is 1/x and tarun's one day work is 1/y
  .so total worked completed of one day by both 1/10.ie 1/x+1/y=1/10.
  now in 4 days completed work by both will be 4/10.
  now the remaining work will be 1-4/10=6/10.
  and this 6/10 work will be completed only by arun .and arun can do the same work in 30 days alone .so 6/10 work will be completed by 6/10*30=18 day.
• 11 years agoHelpfull: Yes(0) No(1)