Question

need some help!
Kamila plans to build a concrete block wall behind her house. The wall will be 12 feet long, 6 feet high, and 8 inches thick. Each concrete block measures 16 inches long by 8 inches wide by 8 inches deep.

How many blocks will Kamila need to build the wall?
Each concrete block has two holes through the middle of the block. The holes are 4 inches wide by 4.5 inches long. What is the volume of one concrete block?

Each concrete block weighs 36.5 pounds. What is the total weight of the concrete wall?
If each block is solid concrete, how much would one block weigh?

Answer 1

@Directrix or someone

Answer 2

anyone?

Answer 3

Do you know how many blocks are needed to build the wall?

Answer 4

We need a plan on how to do this problem.

Answer 5

no one of the questions is actually How many blocks do we need

Answer 6

The wall is a rectangular solid with length, width, and height. You can get the volume of that.

Then, get the volume of one block disregarding the holes in the blocks. Divide that number into the volume of the wall and see if the answer makes sense as being the number of needed blocks.

Answer 7

um okay.. so .. im a little confused with the math can you help me with that please an thank you

Answer 8

Wall: 12 * 6 * (8/12) feet = ? cubic feet

Block: 16/12 * 8/12 * 8/12 = ? cubic feet for one block (disregarding block holes)

Answer 9

i am just gonna do the math now one moment

Answer 10

so for the first one I got .. 48.24 cubic feet is that correct?

Answer 11

but the second one im confused by

Answer 12

Let me see.

I got an integer for the volume of the wall. No decimals. Run your product through again.

Do not approximate 8/12. Let it go through and divide out with some of the other numbers.

Answer 13

okay one moment

Answer 14

wait i got the same answer.. what do i do with the 8/12?

Answer 15

Are you using the calculator on your neck to get the product or are you using something else?

Answer 16

the one on my computer

Answer 17

@Directrix should i use something else

Answer 18

Look at this:

http://www.wolframalpha.com/input/?i=12+*+6+*+%288%2F12%29+%3D

Answer 19

oh okay

Answer 20

The algorithm by which your calculator works is first approximating 8/12 and getting a decimal. Then, it multiplies.

Answer 21

ohhh okay i guess i was doing that reverse.. now the second one was not working but here i will put it through the thing that you used

Answer 22

What is this: 16/12 * 8/12 * 8/12 =

Answer 23

when i put it through that it says that it is 0.592

Answer 24

I got 16/27

Answer 25

yea it was that but it had also put it in decimal form

Answer 26

Look at the exact result:

http://www.wolframalpha.com/input/?i=16%2F12+*+8%2F12+*+8%2F12+%3D

Answer 27

oh okay so now that we have those two what do i do next..

Answer 28

This: How many blocks will Kamila need to build the wall?

48 divided by (16/27) = ?

Answer 29

when i tried putting it through that thing it did not work

Answer 30

That thing's official name is WolframAlpha.com and is known by me as "the Wolf."

Grouping symbols are extremely important in mathematics and especially with the Wolf.

After I enter something, I look underneath to see how the Wolf is interpreting what I entered.

http://www.wolframalpha.com/input/?i=48%2F%28%2816%2F27%29%29+%3D

Answer 31

So, 81 blocks.

Answer 32

okay.. thanks ! :) can you help me figure everything else out please

Answer 33

The volume of the block if it were solid was 16/27 cubic feet.

Answer 34

yea

Answer 35

There are two rectangular solid holes in the block.

You have to get the volume of each and subtract them from the volume of the solid block.

Answer 36

What are the dimensions of the rectangular hole: length, width, and height.

Answer 37

okay um well per block they are 16 inches long, 8 inches wide and 8 inches deep

Answer 38

No

Answer 39

The dimensions of one of the rectangular holes in the block.

Answer 40

ohh not the block okay let me try to figure that out .. 1 moment

Answer 41

how do i figure it out for the volume of it? The dimensions are 4in and 4.5 in

Answer 42

What is the height of the hole in the block?

Answer 43

im not sure it just has 4 in and 4.5 in pointing in the block

Answer 44

The rectangular solid hole in the block has 3 dimensions. You were given the dimensions of its base. Its height is the same as the height of the original block, so 8 inches.

Answer 45

okay .. im a litte confused.. what is the formula to solve it with

Answer 46

Like a pack of gum