You must be able to do 2A. just think a little.
Maybe you could have a go at some of the others, why don't you show the forum what you have attempted.
My stats knowledge is very rusty, I'd have to do some research but some of the other questions don't look like they would be that hard.
I think in 2b and 2c you would have to find the new standard deviation for the sample size and then find the z score and then use your z-score tables to find areas (probabilities). Like I said, my stats knowledge is poor. But have a go yourself and show the forum what you CAN do.