If 50 ml of 0.2 m nac2h3o2 and 10 ml of 1.0 m hc2h3o2 are diluted to a final volume of 100 ml, what is the ph of the buffer solution?

Most of these look like dilution questions which follow a general pattern; 
Use M1V1 = M2V2 (because moles in a solution stays constant if diluted) 

so, the Concentration before * Volume before = Concentration after * Volume after 

Using the first question as an example; 0.2*50 = 100 * M2 
Rearranging for M2: 0.1 

Therefore the concentration of the final solution is 0.1 M 
we know that to work out pH you must use negative logs to base 10; i.e. -log(0.1) gives you the pH for this solution which is 1

Inot sure what it is i sorry : ((