Here are some examples:
Does math help us in these situations? In general, based on 50 years of experience, I'd say It's seldom any help.
Why? Too many considerations in each of these decisions are not mathematical.
I'll explain - many decisions are made in a logical manner, based on rational evaluation of the evidence. But in many other cases we are intuitive, or emotional; the options are not easily compared, and we don't have numerical criteria that can be mathematically evaluated.
I know about car-buying decisions because I worked in automotive publishing for 25 years. No matter how much comparison information you give people in advance, they often as not will choose whatever they want on the day they go shopping. Not what they said they would buy.
I had the chance to drive a Tesla, the electric sportscar. It was red; it was fast; it didn't handle as well as my current car. I didn't like it; I certainly didn't need it. After my drive the Tesla salesman asked me what car I thought I would buy next. Based on my whims, my shopping habits, and my needs, I said "A Ford Transit Connect."
He was stunned - "That's $20,000! It's a mini-truck! A commercial vehicle!" That's right. Nothing at all like his product, but certainly a usable option for me and one I liked better than his fast little electric sportscar.
But not rational. Not mathematical.
I'm not suggesting math can't be involved in some decisions - it's just not useful in 37.78% of decisions (yes, I made that up).