When a certain type of thumbtack is tossed, the probability that it lands tip up is 60%, and the probability that it lands tip down is 40%. All possible outcomes when two thumbtacks are tossed are listed. U means the tip is Up, and D means the tip is Down.

UU  UD  DU  DD

a. What is the probability of getting exactly one Down?
b. What is the probability of getting two Downs?
c. What is the probability of getting at least one Down (one or more Downs)?
d. What is the probability of getting at most one Down (one or fewer Downs)?