If a piece of equipment has a mean time between failures (MTBF)of 500 hours with a mean time to repair (MTTR)of 10 hours,then its uptime or average availability would be
A)0.020 or 2.00%
B)0.980 or 98.00%
C)0.500 or 50.00%
D)1.000 or 100.00%

Question

Quizplus · Accepted Answer

Uptime or average availability can be calculated using the formula: 
Availability = MTBF / (MTBF + MTTR)

Substituting the given values, we get:
Availability = 500 / (500 + 10)
Availability = 0.980 or 98.00%

Therefore, the best choice is B.

If a Piece of Equipment Has a Mean Time Between