2+2= what?

sorry just checking to see if this is real

Afudge recipe calls for 1/2 cup of cocoa if only 1/2 of the recipe is made to how much cocoa should you use

In simplified exponential notation, the expression a^2•a^-3•a 1/a 0

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.