A zoo keeps birds (2-legged) and beasts (four-legged). If the zoo contains 60 heads and 200 feet, how many birds and how many beasts live there? Let X represent the number of birds and Y represent the number of beasts in the zoo.
let X be birds = ? Y be beasts = ? heads = 60 feet = 200 feet of birds = 2 feet of beast = 4 From data we come to know that total animals = X+Y=60____1 total feet = 200 = 2X + 4Y_____2 from equation 1 X= 60-Y put this value of X in equation 2 2(60-Y) + 4Y = 200 120 - 2Y + 4Y = 200 2Y= 200 - 120 2Y = 80 Y = 40 Now from value of Y we can calculate X X + Y =60 X + 40 = 60 Or X = 20 The number of beasts is equal to 40 where as number of birds is equal to 20.
