Answer :
To find out how much cement Shaun needs, we start with the given ratio of sand to cement, which is 7:3. This means for every 7 parts of sand, there are 3 parts of cement.
We are told that 210 kg of sand is used. We need to determine how much cement corresponds to this amount based on the established ratio.
Here's how to solve it step-by-step:
1. Add the parts of the ratio together:
The total parts in the ratio are [tex]\( 7 + 3 = 10 \)[/tex].
2. Find the weight of one part:
Since 210 kg of sand corresponds to the 7 parts of sand in the ratio, we calculate the weight of one part by dividing the total sand by the number of parts for sand:
[tex]\[
\text{Weight of one part} = \frac{210 \, \text{kg}}{7} = 30 \, \text{kg/part}
\][/tex]
3. Determine the weight of the cement needed:
Since cement makes up 3 parts of the ratio, we multiply the weight of one part by the 3 parts of cement:
[tex]\[
\text{Cement needed} = 3 \times 30 = 90 \, \text{kg}
\][/tex]
Therefore, Shaun needs 90 kg of cement to mix with 210 kg of sand to maintain the ratio of 7:3.
We are told that 210 kg of sand is used. We need to determine how much cement corresponds to this amount based on the established ratio.
Here's how to solve it step-by-step:
1. Add the parts of the ratio together:
The total parts in the ratio are [tex]\( 7 + 3 = 10 \)[/tex].
2. Find the weight of one part:
Since 210 kg of sand corresponds to the 7 parts of sand in the ratio, we calculate the weight of one part by dividing the total sand by the number of parts for sand:
[tex]\[
\text{Weight of one part} = \frac{210 \, \text{kg}}{7} = 30 \, \text{kg/part}
\][/tex]
3. Determine the weight of the cement needed:
Since cement makes up 3 parts of the ratio, we multiply the weight of one part by the 3 parts of cement:
[tex]\[
\text{Cement needed} = 3 \times 30 = 90 \, \text{kg}
\][/tex]
Therefore, Shaun needs 90 kg of cement to mix with 210 kg of sand to maintain the ratio of 7:3.
