Can someone explain this to me becasue ive been trying for the past 30 mins and i still dont understand it

Is a deceasing linear model or an exponential decay model likely to be a better fit for the data about remembering? ?

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.

Marla bought a book for $12.95, a binder for $3.49, and a backpack for $44.99. the sales tax rate is 6%. find the amount of tax and the total she paid for these items