Question 258832
Fombitz did some good calculating but read the data incorrectly.
It is .02 not .2
P(both fail)={{{(0.2)(0.2)=0.04}}}
P(neither fail)={{{(0.8)(0.8)=0.64}}}
P(one fails)=P(first fails,second doesn't)+P(first doesn't, second fails)={{{(0.2)(0.8)+(0.8)(0.2)=0.32}}}
Ptotal={{{0.04+0.64+0.32=1}}} (all possible events are covered

Adjusting the work then
P(both fail)={{{(0.02)(0.02)=0.0004}}}   2/100*2/100=4/10000
P(neither fail)={{{(0.98)(0.98)=0.9604}}}
P(one fails)=P(first fails,second doesn't)+P(first doesn't, second fails)={{{(0.02)(0.98)+(0.98)(0.02)=0.0392}}}

If the first doesn't fail how are you going to know if the second one did failed?
Ptotal={{{0.0004+0.9604+0.0392=1}}} (all possible events are covered