Staying on the animal theme, a tourist visits the zoo, and is interested in knowing how many birds and lions are on display. The Zookeeper tells him that between birds and lions there are 30 heads and 100 feet. From this information, can you tell how many birds and lions there are? If so, how many birds and lions are in this zoo?
2007-01-29 14:48:26 · 6 answers · asked by Sexy diva 1 in Science & Mathematics ➔ Mathematics
You only need one unknown variable, x, to answer this question.
30 heads = 30 animals
2x = animals with 2 feet (birds)
4x = animals with 4 feet (lions)
2x + 4x = 30
6x = 30
x = 30/6
x = 5
plug 5 back into the 2x and 4x equations
birds = 2x = 2 * 5 = 10 birds (* 2 feet/bird = 20 feet)
lions = 4x = 4 * 5 = 20 lions (* 4 feet/lion = 80 feet)
2007-01-29 15:00:48 · answer #1 · answered by birdr 2 · 0⤊ 0⤋
Since there are thirty heads and each head has at least two feet that would make 60 feet with 40 extra feet, meaning 20 extra pairs of feet. Twenty lions would have 80 feet and the other twenty feet belong to the ten birds in the zoo. Thirty heads, 100 feet.
2007-01-29 23:00:20 · answer #2 · answered by Anonymous · 0⤊ 0⤋
10 birds and 20 lions
2007-01-29 22:54:51 · answer #3 · answered by ~Zaiyonna's Mommy~ 3 · 0⤊ 0⤋
think of the number of lions and birds is x and y respectively.
x+y=30 (number of heads/total)
4x+2y=100 (4x cause lions have 4 feet, and 2y cause birds have 2)
multiply first equation by 2: 2x+2y=60
subtract from second to get: 2x=40
x=20
20 lions, and 10 birds (30-20)
hope that helps =D
2007-01-29 22:53:16 · answer #4 · answered by Veer 3 · 0⤊ 0⤋
x+y=30
2x+4y=100
y=-x+30
2x+4(-x+30)=100
2x-4x+120=100
-2x=-20
x=20
10 birds, 20 lions
2007-01-29 22:55:41 · answer #5 · answered by Mike 2 · 0⤊ 0⤋
lions have 4 feet, birds two
so we have 30 animals total
L + B = 30
4L + 2B = 100
By elimination
-4L - 4B = -120
4L + 2B = 100
-2B = -20
B = 10
So, L = 20
2007-01-29 22:52:55 · answer #6 · answered by leo 6 · 0⤊ 0⤋