First question:

For any one bag, its weight X, has a distribution is given by

P(underweight) =

Second question:

where are individual bags.

Find E(T) and Var(T)

I've worked through them at the bottom if you're still stuck.

For the first one:

Sorry, I don't have the tables on me. Can you check that?

For the second one:

And

So its distribution is given by