The keyword is "sum" which tells you x, y, and z are being added. One half of the sum means that the sum of the three numbers is going to be divided by 2.
x + y + z
------------
2
1st : Find the volume of the rectangular block:
12 × 10 × 20 = 2400 cm^3.
2nd : Find the volume of a cylinder

Where r is radius & h is height.
so:

= 76.02654222 cm^3
Lastly, divide the volume of the rectangular block by the volume of the cylinder
2400 ÷ 76.026 = 31.5679226
You can't round it up so the answer is F) 31
Answer:
http://www.classzone.com/science_book/mls_grade6_FL/540_547.pdf
Step-by-step explanation:
Remember to do PEMDAS so your answer is not correct, since you multiplied before doing the parentheses/exponents.
Explanation:
3(3)^2- 5(4)
= 3(9) - 5(4)
= 27 - 20 = 7