Question

In a farm, ratio of number of cows to number of hens is 2:3. If the number of legs is 40 more than number of eyes, total of how many hens are there in the farm?​

Answer 1

30 hens, 20 cows.

Explanation:

Step one:

let the number of cows be x

and the number of hens be y

Each cow has 2 eyes, each hen has 2 eyes also.

the total number of eyes is

2x+2y

Each cow has 4 legs, each hen has 2 legs.

the total number of legs is

4x + 2y

Step two:

the number of legs exceeds the number of eyes by 40:

4x+2y - (2x+2y) = 40

open bracket

4x+2y-2x-2y=40

4x-2x=40

2x=40

Divide both sides by 2

x=40/2

x=20

Step three:

we know also that x = 2/3*y, so y = 3/2*x = 3/2 * 20 = 30

30 hens, 20 cows.

Check:

60 + 40 eyes = 100, 60 + 80 legs = 140legs.