Most workers in nanotechnology are actively monitored for excess static charge buildup. the human body acts like an insulator as one walks across a carpet, collecting –50 nc per step. what charge buildup will a worker in a manufacturing plant accumulate if she walks 31 steps?

Sometimes arithmetic problems can be solved much more easily using the dimensional analysis approach. You focus on the units of the given information. Then, you manipulate them applying the laws of algebra where like units cancel, in order to end up with the unit of the unknown.

Given:
-50 nc/step
31 steps
Unknown: charge

Thus,
Charge = -50 nc/step * 31 steps = -1550 nc