TS EAMCET Medical 8 May 2019 Shift 2 Paper

Iii a process, certain amount of mass gets converted into energy. Let all the energy so converted be in the form of photons. If 700 × 1012 Hz is the mean frequency of the photons and if there are approximately 1030 photons, what is the approximate mass that is converted into photons? (Assume h = 6.6 × 10−34 J s, c = 3 × 108ms−1)