Help me with number 11 and number 13 please, ASAP.

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 the difference between regular convex and concave polygons

Rectangle leg this 11feet and perimeter of 38feet what is the width of the rectangle in feet