Question

a farmer has ducks and cows the total number of ducks and cows is between 20and40 the ratio of the total number of ducks legs to the total number of cows leg is 5:9 what is the total numbers of ducks and cows in the farm.

Answer 1

Let "L" = total # of legs.

Let "H" = total # of heads.

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L = 2H + 24

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# of legs = 4c + 2d where c = # of cows and d = # of ducks

# of heads = c + d

Now

H=c+d

L=4c+2d

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Equations:

Since L = 2H + 24,

4c + 2d = 2(c+d) + 24

4c+2d = 2c+2d+24

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2c = 24

C = 12 (# of cows)