[WalterBright]

An engineer who does not understand the math is not an engineer, but a technician. Technicians can do very good work as the result of experience. But knowing the math behind it is what makes an engineer.

Credentialism is why the recruiter asked the simple math question.

[WalterBright]

I remember an engineer who was trying to solve a noise problem in an analog circuit. He spent days trying various combinations of resistors and capacitors. Finally, a real engineer stepped in, did a quick calculation, and picked the correct resistor and capacitor and solved the problem in a few minutes.