Calculation of Ore Required to Obtain 400 grams of Copper

To determine how much ore is required to obtain 400 grams of copper, we need to consider the percentage of copper present in the ore.

1. Determine the amount of copper in the ore:

Given that the ore contains 5% copper, we can calculate the amount of copper present in the ore using the following formula:

Amount of copper = (Percentage of copper/100) * Total weight of ore

Using the given information, we can calculate the amount of copper as follows:

Amount of copper = (5/100) * Total weight of ore

2. Calculate the weight of ore required to obtain 400 grams of copper:

To find the weight of ore required to obtain 400 grams of copper, we need to rearrange the formula from step 1:

Total weight of ore = Amount of copper / (Percentage of copper/100)

Substituting the known values, we get:

Total weight of ore = 400 / (5/100)

Simplifying the expression, we have:

Total weight of ore = 400 / 0.05

3. Calculate the total weight of ore:

Dividing 400 by 0.05, we find:

Total weight of ore = 8,000 grams

Therefore, 8,000 grams of ore are required to obtain 400 grams of copper.

Summary:
- The ore contains 5% copper.
- To find the weight of ore required to obtain 400 grams of copper, we used the formula:
Total weight of ore = Amount of copper / (Percentage of copper/100)
- By substituting the values, we found that 8,000 grams of ore are required to obtain 400 grams of copper.

8 kg