For example, in a shell-and-tube problem, you might check: "Did I correctly calculate the shell inside diameter (Ds) from the tube count?"
Here is the critical truth:
The first three links were sketchy — pop-up ads for “instant download, $19.99.” The fourth was a university repository, locked behind a student login she no longer had. The fifth led to a defunct forum from 2009, where a user named “ThermoJoe” had posted: “Email me for solutions, but only if you promise to actually learn the material.”
For students, the solution manual is a study aid. It allows them to practice obscure problems that might not be covered in lectures, giving them a broader exposure