How do you solve the acid/base chemistry problem.. What is the pH of a solution?

The reaction that will happen when you combine these two solutions is:

HCl + NaOH H2O + NaCl.

In your case, you are starting with more HCl than you have NaOH. Consequently, you can just treat this like a stoichiometry and limiting reactant problem.

First convert the molarity and the volume of HCl into moles HCl, and do the same with the NaOH. Determine how many moles of HCl you have remaining (how much excess HCl you have) by subtracting the moles of NaOH from the moles of HCl.

Now, that number of moles of HCl is in 60 mL, right? so you can calculate the molarity of HCl in the final solution. Since HCl is a strong acid, just take the -log of the HCl concentration to give you the pH of the solution.