P is able to do a piece of work in 15 days and Q can do the same work in 20 days. If they can work together for 4 days, what is the fraction of work left?

Options
1) 8/15
2) 7/15
3) 11/15
4) 2/11

• p=1/15, q=1/20
  togethr 4 days work=4*(1/15+1/20)=7/15
  fraction of work left is=1-7/15=8/15
  ans is 1
  
• 9 years agoHelpfull: Yes(17) No(0)
• not a level of elitmus question
• 9 years agoHelpfull: Yes(8) No(0)
• both can complete the work in = 20*15/35=60/7
  
  so, in 60/7 they can complete the work together.
  then in 4 days they can complete the work ( 7/60)*4= 7/15
  then,left work= 1-(7/15)= 8/15
• 9 years agoHelpfull: Yes(5) No(0)
• Ans:1)8/15
  work done together in 4 day is
  =4*(1/15+1/20)
  =7/15
  so left work is (1-7/15)=8/1
• 9 years agoHelpfull: Yes(2) No(1)
• P=15 Q=20
  LCM OF (P,Q)= 60
  P does 4 unit of work and Q can do 3 unit of work in a day..
  working together for 4 days fraction of job completed 7x 4=28
  remaining work 60-28=32
  fraction of work left= 32/60=8/15
• 9 years agoHelpfull: Yes(1) No(0)
• p's one day work=1/15
  Q's 1 day work=1/20
  p+Q one day work= 1/15 +1/20=7/15
  remaining=1-7/15=8/15
• 9 years agoHelpfull: Yes(1) No(1)
• by fraction method
  A -> 1/15
  B -> 1/20
  THEY DO THE WORK 4 DAYS TOGETHER
  SO, 4/15 + 4/20
  4/15+ 1/5
  = 7/15(WORK DONE)
  WORK LEFT = 1-7/15
  => 8/15
  SO, THE ANSWER IS A) 8/15
  
• 9 years agoHelpfull: Yes(1) No(0)
• Right Ans is 8/15
• 9 years agoHelpfull: Yes(1) No(0)
• LCM(15,20)=60
  therefore total work=60 units
  one day work of P=60/15=4 units
  one day work of Q=60/20=3 units
  After 4 days amount of work done= 4*(4+3)=28
  therefore remaining work=28/60=8/15 Answer
• 9 years agoHelpfull: Yes(1) No(0)
• P's 1 day work=1/15
  Q's 1 day work=1/20
  Therefore, (P+Q)'s 1 day work=1/15+1/20=7/60
  Their 4 days work=7/60*4=7/15
  Thus, remaining work=1-7/15=8/15
  Ans:option 1
• 9 years agoHelpfull: Yes(0) No(0)
• ans:option (1)
  
  work done by P in 1 day=1/15.
  work done by Q in 1 day=1/20.
  Total work done by P and Q in 1 day=1/15+1/20=7/60.
  Thus in 4 days,work done=4*7/60=7/15.
  Work left=1-7/15=8/15.
  
  
• 9 years agoHelpfull: Yes(0) No(0)
• work done by p in 1 day=6.67%
  work done by q in 1 day=5%
  so work done by both in 4 days=46.68%
  work left is= 53.32%
  53.32% in fraction is same as 8/15
• 9 years agoHelpfull: Yes(0) No(0)
• Ans :1) 8/15
• 9 years agoHelpfull: Yes(0) No(0)
• Ans: 1) 8/15
• 9 years agoHelpfull: Yes(0) No(0)
• Option 2
  p work per day=1/15
  Q work per day=1/20
  total work of P and Q is (7/60)*4
• 9 years agoHelpfull: Yes(0) No(0)
• ans= 8/15
• 9 years agoHelpfull: Yes(0) No(0)
• (1/15+1/20)*4=8/15
• 9 years agoHelpfull: Yes(0) No(0)
• Ans is 8/15
• 9 years agoHelpfull: Yes(0) No(0)
• ans is 8/15
  now take lcm of both's working days is 60 i.e. they do 60 unit work together.
  here 4 unit work and 3 unit work is done by a and b respectively in one day.
  so they do 5 unit work regularly
  in 4 days they will completete (4*7)unit work and the left work is here is (60-28)=32
  so the fraction of the left work is =left work/total work=32/60
  so the ans is 8/15
• 7 years agoHelpfull: Yes(0) No(0)