. Father is 5 times efficient then son. and can do work in 40 days earlier. in how many days they can do work together?

• As we know effeciency is inversely proportional to number of days.
  
  Here ,Father is 5 times efficient tan his son.
  Let,the number of days taken by sun be x days.
  the number of days taken by his father=x/5 days
  
  According to question,x/5=x-40
  this will give x=50 days
  
  so, father will take(50-40)=10 days
  The work done in one day by father and son=1/50 +1/10 =6/50=3/25
  
  so, the number of days to complete the work will be 25/3.
• 12 years agoHelpfull: Yes(15) No(0)
• let son can do the work in x days
  So father being 5 times efficient does it in x/5 days
  ..
  x-x/5=40
  S x=50
  So son 1 day work=1/x
  Father one day work=5/x
  now...
  1/50 + 5/50=6/50
  .
  So both will complete in 8.33 days
• 12 years agoHelpfull: Yes(10) No(0)
• let son can complete wrk in 'x' days
  then,
  father can complete it in = x/5 days also, = (x-40)days
  x/5 = x-40
  which gives x = 50.
  x/5 = 10
  both togthr can do the work in = 1/50 + 1/10 = 6/50
  = 50/6 = 8 2/6 days
• 12 years agoHelpfull: Yes(5) No(0)
• 5(40+x)=x
  x=50 and x5=10
  both will wok in..
  150+1/10=50/6 days..
  ie aprox 8.2 days
• 12 years agoHelpfull: Yes(0) No(0)