A particular laser consumes 100.0 Watts of electrical power and produces a stream of 2.551019 1173 nm photons per second. A particular laser consumes 100.0 Watts of electrical power and produces a stream of 2.551019 1173 nm photons per second. What is the percent efficiency of the laser in converting electrical power to light?

I just posted this question and someone gave me the wrong answer, it is not 52.4%.. please help