Graduate Management Admission Test (GMAT) Practice Test

Choosing to calculate the difference between each liquid's concentration and the desired concentration is the essential first step when combining two liquids to achieve a specific concentration. This approach allows you to understand how far each liquid's current concentration is from your target concentration, which is critical for effectively determining the proportion of each liquid needed for the desired result.

By knowing the differences in concentration, you can apply the concept of dilution or concentration adjustments more accurately. This calculation informs the subsequent steps you need to take, whether you're adding one liquid to dilute the other or needing to mix them in a specific ratio.

In contrast, assessing the density of each liquid or checking the temperature, while potentially relevant in other contexts, does not directly aid in calculating the necessary concentration adjustments initially. Thorough mixing is also not beneficial unless you have established how much of each liquid you need to combine. Therefore, understanding the initial differences in concentration serves as a vital foundation for the entire mixing process.