One man, 3 women and 4 boys can do a piece of work in 96 hours, 2 men and 8 boys can do it in 80 hours, 2 men & 3 women can do it in 120 hours. 5 Men & 12 boys can do it in how many hours?
(A) 39 1/11 hrs (B) 42 7/11 hrs ( C) 43 7/11 days (D) 44hrs

• m+3w+4b=1/96...1
  2m+8b=1/80...2
  2m+3w=1/120....3
  2*eq(2)
  4m+16b=1/40...4
  eq(3)+eq(4)
  5m+12b+(m+3w+4b)=1/40+1/120
  5m+12b=11/480
  so ans 43 7/11
• 13 years agoHelpfull: Yes(14) No(9)
• m+3w+4b 1hrs work=1/96---1
  2m+8b=1/80---2
  2m+3w=1/120---3
  so from 2 eq
  m+4b=1/160 putting this value in 1 equation
  (m+4b)+3w=1/96
  so 1/160+3w=1/96
  3w=2/480 so 1w=2/480*3 ;
  putting w value in 3 equation
  1m=1/480;
  putting all values in 1st
  1b=1/480*2
  so 5m+12b=5*1/480+12*1/480*2=11/480
  so work will be done in 480/11
  
• 9 years agoHelpfull: Yes(3) No(1)
• Let’s assume man, women and boy as M, W, B respectively.
  So, m+3W+4B=1/96 ------- (1)
  2M+8B=1/80 -------- (2)
  2M+3W=1/120 --------- (3)
  As per above equation.
  4M+16B=1/40 --------- (4)
  eq(3)+eq(4)
  5M+12B+(M+3W+4B) = 1/40+1/120
  5M+12B=11/480 = 43 7/11 hrs.
• 5 years agoHelpfull: Yes(0) No(0)
• (m + 3w + 4 b) = 1/96
  
  2m + 6w + 8b) = 1/48————1
  
  (2m + 3 w ) = 1/120————2
  
  (2m + 8b) = 1/80————-3
  
  1 -,3 gives 6w = 1/120
  
  w= 1/720
  
  From 2 , 2m = 1/120 - 1/240 = 1/240.
  
  5 m = 1/96
  
  From 3 , 8b = 1/80 - 1/240 = 1/120
  
  12 b = 1/80
  
  5m + 12 b =11/480
  
  Answer 43.63 hours .
• 4 years agoHelpfull: Yes(0) No(0)