Question

1 cubic metre of concrete has a weight of 2400 kg 15 of the concrete is water the rest of the concrete are cement, sandand stone The weight of these ingredients are in the ratio 1:2:5 work ouyt the weight of cement, sand and stone in 1 cubic metre of cement

Answer 1

Weight of cement
`= 298.125` Kg

Weight of sand
`= 2 * 298.125 = 596.25` Kg

Weight of Stone
`= 5 * 298.125 = 1490.625` Kg

Explanation:

Given -

The total weight of concrete
`= 2400` Kg

Weight of concrete
`= 15` Kg

The weight of cement, sand and stone is equal to

`2400 - 15 = 2385` Kg

Let
`X` be the weight of cement,

Then weight of sand is
`2X`

Weight of stone is
`5X`

`X + 2X + 5X = 2385`

On solving the above equation, we get -

`8 X = 2385 \\X = 298.125`

Thus,

Weight of cement
`= 298.125` Kg

Weight of sand
`= 2 * 298.125 = 596.25` Kg

Weight of Stone
`= 5 * 298.125 = 1490.625` Kg

Answer 2

Cement = 255 kg,

Sand = 510 kg,

Stone = 1275 kg.

Explanation:

We have been given that 1 cubic meter of concrete has a weight of 2400 kg and 15% of the concrete is water. The rest of are cement, sand and stone.

Let us find 15% of 2400.

`\text{Amount of water in concrete}=(15)/(100)* 2400`

`\text{Amount of water in concrete}=15* 24`

`\text{Amount of water in concrete}=360`

The amount of cement, sand and stone will be:
`2400-360=2040`.

We are also told that the weight of cement, sand and stone are in the ratio 1:2:5.

We can represent this information in an equation as:

`1x+2x+5x=2040`

`8x=2040`

`(8x)/(8)=(2040)/(8)`

`x=255`

Therefore, the weight of cement in 1 cubic meter of concrete is 255 kg.

`\text{Weight of sand}=2x`

`\text{Weight of sand}=2*255`

`\text{Weight of sand}=510`

Therefore, the weight of sand in 1 cubic meter of concrete is 510 kg.

`\text{Weight of stone}=5x`

`\text{Weight of stone}=5*255`

`\text{Weight of stone}=1275`

Therefore, the weight of stone in 1 cubic meter of concrete is 1275 kg.