Wht do I put?? Can some one help pls

Successful implementation of a new system is based on three independent modules. module 1 works properly with probability 0.96. for modules 2 and 3, these probabilities equal 0.95 and 0.90. compute the probability that at least one of these three modules fails to work properly.

Which basic geometric term has no width, no length, and no thickness? line b. point c. angle d. plane

Solve this problem! extra ! 3025/5.5 = a/90.75