The alloy contains 62% tin and 38% lead. How many grams of tin and how much lead are in 400g of the alloy.

Let’s represent the total weight of the alloy which is 400 grams as a percentage.
In this case, it will be 100%.
In order to determine the weight of each of the alloy components, it is necessary to multiply the real weight by a percentage.

In this case, for tin we get:
400 * 62% / 100% = 400 * 0.62 = 248 grams of tin.

Find the amount of lead.
400 * 38% / 100% = 152 grams of lead.

Also, the amount of lead can be determined by subtracting the weight of the tin from the total weight of the alloy.
We get:
400 – 248 = 152 grams.