There are horses and three legged cows there are a total of 63 heads and 240 legs how many horses?
The easiest way is to substract three times the number of heads from the legs and that will give you the amount of horses. The reasoning is as follows:
legs = l
heads = h
horses = x
cows = (h - x)
l = 3(h-x)+4x
l = 3h-3x+4x
l-3h = x
x = l-3h
"On a farm there are horses and three-legged-cows. There are total of 100 heads and 376 legs. How many horses are on the farm?"
100 * 4= 400
400 - 376 =24
100 - 24 = 76
76 horses 24 cows 24 * 3 = 72 (cow legs) 76 * 4 = 304 (horses legs)