What is equivalent to 5^3•5^4

Np4=12np2 with clear explanation.

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.

What is an alternate exterior angle