Anuclear reactor facility has two separate safety systems in place to prevent a nuclear meltdown. they prevent meltdown by shutting down the reactor when the temperature reaches the danger level. the first system shuts down the reactor 80% of the time when the danger level is reached. the second system (which is completely separate from the first) shuts down the reactor 90% of the time when the danger level is reached.
a. use your calculator to do 10 repetitions with the first system alone. theoretically it should successfully shut it down 16 out of 20 times.
b. use your calculator to do 10 repetitions with the second system alone. theoretically it should successfully shut it down 18 out of 20 times.
c. use your calculator to do 20 repetitions with the first and second systems working together. the reactor will successfully shut down if one or both systems are not working.