On Friday, March 1, 2019 at 1:42:26 PM UTC-5, wrote:
I have an overhead light fixture with 3 40 watt bulbs. one of them burnt out. can I replace only the burnt out bulb with an LED bulb? What if any would be the consequinces? Thanks for a reply

You can, but if it's a closed fixture, the LED one may have a shorter life at
the elevated temperature inside from the 80W of the other two bulbs.