The time is recorded from three different clocks as indicated below. the “true” time is exactly 8: 30 a. m.
which of the three clocks is the most precise?
which clock is the most accurate?
which clock(s) show a systematic error?

measurement clock a clock b clock c
1 8: 25.20 am 8: 29 am 8: 36 am
2 8: 25.00 am 8: 31 am 8: 36 am
3 8: 25.10 am 8: 30 am 8: 36 am

Precision is the stability of the results of each clock so Clock C is the most precise.
Accuracy is the closeness to the actual value so Clock B is the most accurate.
There is a systematic error if the accuracy cannot be fixed but the precision can be increased by increasing the number of times the measurement is taken so Clock C has a systematic error.

The  grandmother cell  is a hypothetical  neuronthat represents a complex but specific concept or object.[1]  it activates when a person "sees, hears, or otherwise sensibly discriminates"[2]  a specific entity, such as his or her grandmother. the term was in use at least as early as 1966 amongst staff and students in the department of experimental psychology, university of cambridge, england. a similar concept, that of the  gnostic neuron, was proposed two years later