I know the answer but i'm not sure how i got it, can you help?
2007-10-05 07:35:30 · 8 answers · asked by Michele H 1 in Science & Mathematics ➔ Zoology
People think too much. All the animals have two hind legs. That's 162 hind legs for the 81 animals. That leaves 90 front legs, which only cows have, or 45 cows. That makes 36 chickens. Double check and you get 45 times 4 (180) plus 36 times 2 (72) or 252 legs.
2007-10-05 11:36:55 · answer #1 · answered by Nomadd 7 · 0⤊ 0⤋
There is no one correct answer. Think of it this way...
Each cow has 4 legs, 4X
Each chicken has 2 legs, 2y
Add up the number of legs on the cow and chickens and it is equal to 252.
4x + 2y = 252 Factor out the 2
2(2x + y) = 252 Multiply both sides of the equation by 1/2
2x + y = 126
The important thing to note here is that this is the equation of a line, and many (x,y) coordinates are on this line that satisfy the equation.
Make a table that describes the equation (it's hard to do on this interface so iI'm separating the numbers with a -)
X----2X------Y
10---20---106 20+10=126
20---40-----86 40+86=126
These also work in the original equation...
(4x10) + (2x106) = 40 + 212 = 252
(4x20) + (2x86) = 80 + 172 = 252
Bingo!
2007-10-05 08:08:03 · answer #2 · answered by archaeadoc 5 · 0⤊ 0⤋
enable Cows be X enable poultry be Y as a result, X + Y = 80 one (Given) (Equation a million) extra, 4X + 2Y = 252 (Cows have 4 legs, poultry have 2) (Equation 2) fixing those 2 equations; X + Y = 80 one or 2X + 2Y = 192...(a million) 4X + 2Y = 252...(2) 2Y is cancelled and 2X = ninety => X = 40 5 = form of Cows putting fee of X in any equation, we get Y = 36 as a result, cows are 40 5; poultry are 36. (answer)
2016-10-10 09:01:04 · answer #3 · answered by ? 4 · 0⤊ 0⤋
How do you know the answer?
Call the number of cows, "C", and the number of chickens "K". Then:
4C + 2K = 252
C + K = 81
Solve for C = 45, K = 36. Unless you include the farmer; in that case K = 35.
2007-10-05 07:45:13 · answer #4 · answered by morningfoxnorth 6 · 1⤊ 0⤋
C=chickens
Y=cows
4c+2y=252
c+y=81
Y=81-c
4C+2(81-c)=252
4c+162-2c=252
2c=90
c=45
45+y=81
y=36
45 chickens and 36 cows.
2007-10-05 07:48:29 · answer #5 · answered by Gray J. 2 · 0⤊ 0⤋
162 chickens and 25 cows.
2007-10-05 07:44:28 · answer #6 · answered by Anonymous · 0⤊ 1⤋
45 cows
36 chickens
2007-10-05 07:44:54 · answer #7 · answered by dan 4 · 0⤊ 0⤋
47 cows, 34 chickens
47 X 4 legs = 188legs
+ +
34 X 2 legs = 68
--------------------------------
81 252
heads legs
2007-10-05 07:45:10 · answer #8 · answered by ? 3 · 0⤊ 1⤋