To find the percentage of Allied soldiers that were Russian, you can use the following steps:
1. Calculate the total number of soldiers mobilized by the Allied Powers: 42,000,000 men.
2. Determine the number of Russian soldiers: 12,000,000.
3. Divide the number of Russian soldiers by the total number of soldiers: 12,000,000 / 42,000,000 = 0.2857 (rounded to four decimal places).
4. Convert the result to a percentage by multiplying by 100: 0.2857 * 100 = 28.57%.
5. Therefore, approximately 28.57% of the Allied soldiers were Russian.
