Absolutely correct. One of the most exciting moments in my entire teaching career was when a student during an exam came up with a much simpler solution than I had taught. It was a big disappointment when she later asked me to fill oubt a recommendation for admission to law school.
For the problem at hand, I probably would have said to myself, “Hmm, 50 + 75 is a bit too large, so let’s back off a bit.”