math
posted by Anonymous .
The number of dogs and chickens on a farm add up to 14. The number of legs between them is 36. How many dogs and how many chickens are on the farm if there are at least twice as many chickens as dogs

c >= 2d
c+d = 14
2c+4d = 36
2(14  d) + 4d = 36
28 + 2d = 36
2d = 8
d = 4
so, c = 10
the bit about c>=2d is redundant and unnecessary.