What is the pH of a solution if you mix 250 ml of 3.5M Formic acid and 495 ml of 1.75M LiOH?

Since that's homework. And we don't do your assignments because you would learn nothing. What do you think the answer is... and how did you arrive at that answer.

Just to help you start the solution, please note that:-
There will be an acid base reaction and then your problem will be solved automatically.
To know more, show your calculations first.