Question

Cows and Chickens

Answer 1

Answer:

27 Chickens

Step-by-step explanation:

Represent the chicken with A and the cows with B

Given

$A + B = 30$

A has 2 legs and B has 4; So:

$2A + 4B = 66$

Required

Determine A and B

Make B the subject of formula in the first equation

$B = 30 - A$

Substitute 30 - A for B in the second equation

$2A + 4(30 - A) = 66$

Open the bracket

$2A + 120 - 4A = 66$

Collect Like Terms

$2A - 4A = 66 - 120$

$-2A= -54$

Divide through by -2

$A = 27$

Hence, the farmer has 27 chickens