Question 85207
The total energy radiated by Sun in one day is {{{E = 3.86}}}{{{x}}}{{{10^23}}}{{{x}}}{{{86400}}} = {{{33.35}}}{{{x}}}{{{10^27}}} joules.


The factor 86400 comes as a day has 86400 seconds.


Now, velocity of light is {{{c = 3}}}{{{x}}}{{{10^8}}} m/s


So, the mass of Sun converted to radiation per day is 
{{{m = E/c^2}}}
{{{m=33.35*10^27/(3*10^8)^2}}} kg
{{{m=3.72}}}{{{x}}}{{{10^11}}} kg