Using the order of operations, we have $2^3 + 3^2 - 5^1 = 8 + 9 - 5 = 18$.

To find the total number of animals, we simply add the number of sheep, cows, and pigs: $12 + 6 + 4 = 22$.

The area of a rectangle is found by multiplying the length and width. Therefore, the area of the garden is $10 imes 5 = 50$ square meters.

To find the time at which the second train will overtake the first train, we need to find the time it takes for the second train to travel the distance between the two trains. This distance is equal to the speed of the first train multiplied by the time difference between the two trains. Therefore, the time it takes for the second train to overtake the first train is $rac{60 imes 1}{70 - 60} = 1.5$ hours. Adding this time to the departure time of the second train, we get $11:00 AM + 1.5$ hours = $12:30 PM$.

To find the sale price of the shirt, we need to subtract the discount from the original price. The discount is $20 imes 0.20 = $4$. Therefore, the sale price of the shirt is $20 - $4 = $16$.

To find the number of women who work for the company, we need to multiply the total number of employees by the percentage of women. Therefore, the number of women who work for the company is $100 imes 0.60 = 60$.

The perimeter of a rectangle is found by adding the lengths of all four sides. Therefore, the perimeter of the room is $2 imes (12 + 8) = 40$ feet.

The probability of an event is the ratio of the number of favorable outcomes to the total number of possible outcomes. In this case, the favorable outcomes are the number of blue balls, which is 15. The total number of possible outcomes is the total number of balls, which is $10 + 15 + 20 = 45$. Therefore, the probability of selecting a blue ball is $rac{15}{45} = rac{1}{3}$.

The area of a circle is found by using the formula $A = πr^2$. Therefore, the area of the circle is $π imes 5^2 = 25π$ square centimeters.

To find the average speed of the train, we need to divide the distance traveled by the time taken. Therefore, the average speed of the train is $rac{200}{4} = 50$ kilometers per hour.

To find the sale price of the shoes, we need to subtract the discount from the original price. The discount is $100 imes 0.30 = $30$. Therefore, the sale price of the shoes is $100 - $30 = $70$.

To find the number of men who work for the company, we need to multiply the total number of employees by the percentage of men. Therefore, the number of men who work for the company is $200 imes 0.40 = 80$.

The area of a rectangle is found by multiplying the length and width. Therefore, the area of the room is $15 imes 10 = 150$ square feet.

The probability of an event is the ratio of the number of favorable outcomes to the total number of possible outcomes. In this case, the favorable outcomes are the number of green balls, which is 24. The total number of possible outcomes is the total number of balls, which is $12 + 18 + 24 = 54$. Therefore, the probability of selecting a green ball is $rac{24}{54} = rac{1}{2}$.

The circumference of a circle is found by using the formula $C = 2πr$. Therefore, the circumference of the circle is $2π imes 8 = 16π$ centimeters.