Answer :
Let's use algebra to solve this problem:
Let x be the number of emus (two-legged animals) on Henry's farm.
Let y be the number of alpacas (four-legged animals) on Henry's farm.
Each emu has 2 legs, and each alpaca has 4 legs. The total number of legs on the farm is 60.
Therefore, we can create an equation based on the information given:
2x (legs from emus) + 4y (legs from alpacas) = 60
From the information provided, we also know that there are 18 animals in total:
x (number of emus) + y (number of alpacas) = 18
Now, we have a system of equations to solve for the number of each type of animal on Henry's farm. We can use substitution or elimination to find the values of x and y.
Let's start by solving the second equation for x:
x = 18 - y
Substitute this expression for x into the first equation:
2(18 - y) + 4y = 60
36 - 2y + 4y = 60
2y = 24
y = 12
Now, substitute the value of y back into x = 18 - y:
x = 18 - 12
x = 6
Therefore, there are 6 emus and 12 alpacas on Henry's farm.
