In a solution, 4 parts solvent to 1 part solute are present. What percent of the solution is solute?

In a solution, 4 parts solvent to 1 part solute are present. What percent of the solution is solute?

• A. 20%
• B. 80%
• C. 5%
• D. 25%

Answer: (A)

Understanding percent by parts means you take the amount of solute and divide it by the total amount of solution, then convert to a percentage. Here, there are 4 parts solvent and 1 part solute, so the total is 5 parts. The solute makes up 1 part out of 5, which is 1/5 = 0.2, and 0.2 × 100% = 20%. So the solute is 20% of the solution. The other options would correspond to different ratios (for example, 80% would require the solute to be 4 of 5 parts, 5% would come from 1 of 20 parts, and 25% from 1 of 4 parts), which don’t match the given 4 to 1 ratio.

Understanding percent by parts means you take the amount of solute and divide it by the total amount of solution, then convert to a percentage. Here, there are 4 parts solvent and 1 part solute, so the total is 5 parts. The solute makes up 1 part out of 5, which is 1/5 = 0.2, and 0.2 × 100% = 20%. So the solute is 20% of the solution. The other options would correspond to different ratios (for example, 80% would require the solute to be 4 of 5 parts, 5% would come from 1 of 20 parts, and 25% from 1 of 4 parts), which don’t match the given 4 to 1 ratio.