Amount- Ratio

[Guest]

In one kind of concrete the parts of cement, sand, and gravel are as 1:2:4. Another kind 3 parts are as 1:2:5. Determine how much more concrete in pounds needed in 1 ton of one than the other.

Let 1st kind = A
Let 2nd kind = B

Let C = Cement
Let S = Sand
Let G = Gravel

A = 7 parts- 1/7 cement, 2/7 sand, 4/7 gravel.

B = 8 parts- 1/8 cement, 2/8 sand, 5/8 gravel.

1 ton = 2000 pounds.

I know this is similar to the other concrete problem. Even after explanation I thought I understood but I don't.

[Guest]

"Determine how much more concrete in pounds needed in 1 ton of one than the other."

I assume you mean how much more cement in pounds needed in 1 ton of one than the other?.

How many pounds are in 1 ton. Is it 2240 pounds in 1 ton.

[Guest]

It should be cement.

Typo error - sorry.

For U.S. pounds in 1 ton - 2000

[Guest]

If you assume 1 ton of (dry cement,sand and gravel) makes 1 ton of concrete.....ignoring need for water and any chemical changes etc.... then Mix A will have 1/7 ton of cement and Mix B will have 1/8 ton cement.

difference ( A - B) = (8/56 - 7/56) = 1/56 of 2000 pounds = 286 pounds.

[Guest]

I don't know what buttons I was pressing on my calculator when I got 286 pounds...? ? ? ?.

It should read...............

1/56 of 2000 pounds = 2000/56 = 35.7 pounds......

and if you had taken UK tons = 2240 pounds it would work out even numbers...

2240/56 = 40 pounds

[Guest]

Thank you.