Answer:
Probability (Both fail) = 0.001369
Probability (None fails) =0.927369
Probability (at least one fails) = 0.072631
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