25 man can do the work in 6 days and 12
girl can do same amount of work in 25 days

in how many days boy and girl together complete the 1/5 work

• one man's one day work 1/150
  girls one day work 1/300
  combinedly work will be completed in 100 days..1/5 work will be done in 20 days
• 10 years agoHelpfull: Yes(6) No(1)
• 25 men's one day work= (1/6)*(1/25)=1/150
  similarly,
  one girl's one day work=(1/25)*(1/12)=1/300
  when working together,they complete the work=
  (1/150)+(1/300)=> 1/100 ==> i.e complete 1/100 of work in 1 day
  which implies they complete the work in 100 days , when working together.
  therefore they will complete (1/5)th of the work in 100*(1/5)=20 days.
• 10 years agoHelpfull: Yes(1) No(0)
• given:
  25man in 6days
  12girls in 25days
  let x=days to finish the work
  
  man=25/6
  girl=12/25
  man+girl=0.2/x
  
  solution:
  
  (25/6)+(12/25)=0.2/x find the LCD
  55(25)/150+6(12)/150=0.2/x
  1375/150+72/150= 0.2/x
  1447/150=0.2/x
  1447x=150(0.2)
  1447x=30
  x=30/1447
  x=0.02 days
• 10 years agoHelpfull: Yes(0) No(0)