Please help I'm stuck with this question?

Question

The ratio of gravel to sand to cement in concrete is 4 : 2 : 1.
How many m3 (that's the little 3... "cubed") of each is required to make 10m3 ("cubed") of concrete?

First who gets right with small explanation gets 10 points!

Answer 1

Here's a quick answer that makes intuitive sense. If you took 4 cubic meters of gravel, 2 cubic meters of sand, and one cubic meter of cement you would get 7 cubic meters of the concrete you need.

But you don't want 7 cubic meters. You want ten which is 10/7 of what you get this easy way. So just multiply each measurement by 10/7 = 1.43

That gives you 5.71 cubic meters of gravel and 2.86 cubic meters of sand, and 1.43 cubic meters of cement.

Answer 2

Let C be the amount of cement.

Amount sand 2C

Amount gravel 4C

Total 7C = 10. So, C = 10/7, sand is 20/7, and

gravel is 40/7 cubic meters. Check: 40/7 + 20/7 + 10/7 = 10.

Answer 3

First, you need to divide the 10 m^3 into 7 equal parts (4+2+1).

10/7 = 1.43

Now:

o gravel = 4 x 1.43 = 5.72
o sand = 2 x 1.43 = 2.86
o concrete = 1 x 1.43 = 1.43

Add them all up and you get 10.01 m^3 (a bit of round-off error)

Answer 4

4/7 x 10 = gravel
2/7 x 10 = sand
1/7 x 10 = cement

Answer 5

Total ingredients = 7m³.
4/7ths of 10 = 40/7 = 5.7m³ of Gravel.
2/7ths of 10 = 20/7 = 2.9 m³ of sand
1/7th of 10 = 1.4 m³ of cement.
Total = Exactly 10 m³

Answer 6

The correct answer is you call the ready mix plant and get your 10 cubic meters (or yards here in the states) and they figure out the correct proportions to supply the mix you asked for.

Answer 7

no one is right...this ratio is by WEIGHT, not volume. so we need to find out the specific gravity of each then do the math.

Answer 8

ummm ... 10m3 of each. The ration didn't change, just the multiplyer did. If you have a constant m and you need 10m, then you would need 10 x each item.