Answer:
1755 minutes
Explanation:
To determine the mean time between failures in the equipment you need to calculate the time in which this equipment is functional. You know that the 97.5% of the time the equipment is working, so the other 2.5% the equipment is failing; this means that 45 min is 2.5%. With a rule of three you can calculate the time of working (97.5*45)/(2.5) = 1755 minutes. So between failure the equipment can work 1755 minutes.