Homework help trying to figure out which option is accurate:

LetEbe the event that the life of a certain light bulb is at least250hours andFthat the life is at most550hours. Describe the following sets.

(a)EF

• The light bulb lasts at least250hoursandthe light bulb lasts at most550hours.
• The light bulb lasts at least250hoursorthe light bulb lasts at most550hours.
• none of these

(b)E^C

• none of these
• The light bulb does not lastat most 550 hours.
• The light bulb lastsat most 550 hours.
• The light bulb lastsat least 250 hours.
• The light bulb does not lastat least 250 hours.

(c)E^CF^C

• none of these
• The light bulbdoes not lastat least250hoursorthe light bulbdoes not lastat most550hours.
• The light bulbdoes not lastat least250hoursandthe light bulblastsat most550hours.
• The light bulblastsat least250hoursandthe light bulbdoes not lastat most550hours.
• The light bulbdoes not lastat least250hoursandthe light bulbdoes not lastat most550hours.