grass in lawn grow equally thick in uniform rate. it takes 24days for 70cows and 60 days for 30 cows to eat the whole of the grass. how many cows are needed to eat the grass in 96days?

• 24 days 70 cow
  60 days 30 cow
  96 days = ??cow
  comm diff of days is 36
  and comm diff of cows is 40
  so 96 days 10 cows will graze...
• 12 years agoHelpfull: Yes(7) No(26)
• 20 cows
  
  g - grass at the beginning
  r - rate at which grass grows, per day
  y - rate at which one cow eats grass, per day
  n - no of cows to eat the grass in 96 days
  
  From given data,
  g + 24*r = 70 * 24 * y ---------- A
  g + 60*r = 30 * 60 * y ---------- B
  g + 96*r = n * 96 * y ---------- C
  
  Solving for (B-A),
  (60 * r) - (24 * r) = (30 * 60 * y) - (70 * 24 * y)
  36 * r = 120 * y ---------- D
  
  Solving for (C-B),
  (96 * r) - (60 * r) = (n * 96 * y) - (30 * 60 * y)
  36 * r = (n * 96 - 30 * 60) * y
  120 * y = (n * 96 - 30 * 60) * y [From D]
  120 = (n * 96 - 1800)
  n = 20
  
  Hence, 20 cows are needed to eat the grass in 96 days
• 12 years agoHelpfull: Yes(5) No(0)
• @DIPTANSHU:: u get ans 21.5.... 21 cow and half cow??? ha ha lol
• 12 years agoHelpfull: Yes(3) No(6)
• 96*x=24*70+30*60
  96x=1680+1800
  96x=3480
  x=36.25
• 12 years agoHelpfull: Yes(3) No(2)
• 18 cows...
• 12 years agoHelpfull: Yes(2) No(12)
• 20
  g - grass at the beginning
  r - rate at which grass grows, per day
  y - rate at which one cow eats grass, per day
  n - no of cows to eat the grass in 96 days
  g + 24*r = 70 * 24 * y
  g + 60*r = 30 * 60 * y
  g + 96*r = n * 96 * y
  Solving, n = 20.
• 9 years agoHelpfull: Yes(2) No(1)
• g - grass at the beginning
  
  r - rate at which grass grows, per day
  
  y - rate at which one cow eats grass, per day
  
  n - no of cows to eat the grass in 96 days
  
  From given data,
  
  g + 24*r = 70 * 24 * y ---------- A
  
  g + 60*r = 30 * 60 * y ---------- B
  
  g + 96*r = n * 96 * y ---------- C
  
  Solving for (B-A),
  
  (60 * r) - (24 * r)
  
  = (30 * 60 * y) - (70 * 24 * y) 36 * r
  
  = 120 * y ---------- D
  
  Solving for (C-B),
  
  (96 * r) - (60 * r)
  
  = (n * 96 * y) - (30 * 60 * y) 36 * r
  
  = (n * 96 - 30 * 60) * y 120 * y
  
  = (n * 96 - 30 * 60) * y
  
  [From D] 120 = (n * 96 - 1800)
  
  n = 20
  
  Hence, 20 cows are needed to eat the grass in 96 days.
• 11 years agoHelpfull: Yes(1) No(0)
• 24 days - 70 cows
  60 days at same grass= 28 cows.....
  2 cows eats the extra grass which grows in 36 days.....
  extra grass in [96-24] dys eaten by 4 cows...
  24-days-- 70 cows
  96 days- 17.5 cows
  so total 17.5+4=21.5 cows....
  is it possible... please whats d options??
• 12 years agoHelpfull: Yes(0) No(8)
• what r the options?? it's coming 15
• 12 years agoHelpfull: Yes(0) No(0)