Use the formula i=prt, where i is the interest earned, p is the principal, r is the rate (as a decimal fraction) and t is the elapsed time, in years.
Here i = $72 = $1200 r (9/12) (9 months is 9/12, or 3/4, of 1 year)
Reducing,
$72 = $900r
Solving for r, r=0.08, or 8 percent per year.
Using a system of equations, it is found that:
- There are 8 chickens in the yard.
- There are 16 pigs in the yard.
-----------------------------------------
This question is solved using a system of equations. I am going to say that:
- x is the number of chickens.
-----------------------------------------
- A chicken has 1 head, as do a pig.
- There are 24 heads.
Thus:

-----------------------------------------
- A chicken has 2 feet.
- A pig has 4 feet.
- In total, there are 80 feet.
Thus:

-----------------------------------------
Number of chicken:
Since 






There are 8 chickens in the yard.
-----------------------------------------
Number of pigs:

There are 16 pigs in the yard.
A similar problem is given at brainly.com/question/24104709
Answer :- Just try area/2 or half the area of the triangle