Answer:
Probability (Both fail)  = 0.001369
Probability (None fails) =0.927369
Probability (at least one fails)   = 0.072631
Step-by-step explanation:
given data 
Probability (fail) P = 0.037
two alternators is  independent
solution
we get here first  probability that both will fail will be 
Probability (Both fail) = 0.045²    ................1
Probability (Both fail)  = 0.001369
and 
now we get probability that neither will fail 
Probability (None fails) = (1-0.037)²              ...............2
Probability (None fails) =0.927369
and 
now we get probability that at least one fails 
Probability (at least one fails)  = 1 - Probability (non fails)     .................3
Probability (at least one fails)   = 1 - 0.927369
Probability (at least one fails)   = 0.072631