A certain work can be completed in 15 days by 12 men, 18 women and 24 boys respectively. How long would 3 men, 9 women and 18 boys have to work together to do it ?

• A certain work can be completed in 15 days by 12 men, 18 women and 24 boys respectively.
  
  so
  work of 1 man = work of 1.5 woman = work of 2 boys
  9 women = 6 men
  18 boys = 9 men
  3 men, 9 women and 18 boys = 3+6+9=18 men
  
  A certain work can be completed in 15 days by 12 men,
  18 men will complete the work in 15*12/18 = 10 days.
  
• 11 years agoHelpfull: Yes(6) No(1)
• 12 men do in 15 days
  so 1 man can compleat it with in 12*15 days
  same for woman 18*15
  and boy 24*15
  so one day work
  m=1/(15*12)
  w=1/(18*15)
  b=1/(24*15)
  now m+w+b=(1/x)
  on solving x=10 ie days
• 11 years agoHelpfull: Yes(1) No(1)