P can complete a piece of work in 20 days and Q in 30 days. P worked alone for 4 days and then Q completed the remaining work along with R in 18 days. In how many days can R working alone complete the work?

• Ans:- 90 days
  
  If R alone can complete the work in 'x' days, then 1 day work of R is 1/x
  Here complete work=P's 4 days work + (Q+R)'s 18 days work
  1=(4/20) +18[(1/30)+(1/x)]
  1/x=1/90
  
• 8 years agoHelpfull: Yes(4) No(0)
• work done by p in 1 day=1/20
  4 days work=4/20
  1/5 part will be completed
  remaining 4/5 will done by Q and R in 18 days
  whole work will be done by 4/5*18=72/5
  1 day work by Q+R=5/72
  R=5/72-1/30
  R 1 day work=13/360
  whole work will be completed in 360/13
  
• 11 years agoHelpfull: Yes(1) No(4)
• ans 45
  p--> 1day :1/20;
  q-->1/30
  so p 4days -->1/5
  q+r-->1/18 in 1 day
  but q does 18/30 in 18 days so remaining work done by r is 1-18/30=2/5 in 18 days
  s0 one day work will be 1/45 so work will be completed in 45 days
  
• 12 years agoHelpfull: Yes(0) No(12)
• P one day work=1/20
  Q one day work=1/30
  P's 4 day work=4*1/20=1/5
  remaining work=1-1/5=4/5
  4/5 work is done by Q and R in 18 days
  1 work done by Q and are in 18/(4/5)=45/2
  one day work of(Q+R)=2/45
  i.e, 1/30+1/R=2/45
  1/R=2/45-1/30=1/90
  So, R takes 90 days
• 6 years agoHelpfull: Yes(0) No(0)
• p do 1/20 work in a day
  hence it comlete 4/20 = 1/5 work in 4 days
  remaining work = 1-(1/5) = 4/5
  hence r+q do 4/5 work in 18 days
  hence in 1 day r+q done 2/45 work
  q done 1/30 work in a day
  hence work done r in a day = (2/45) - (1/30) =1/90
• 6 years agoHelpfull: Yes(0) No(0)