please answer

Assume the sun is converting four ] H nuclei into one * He and that eventually it uses up 13% of its central mass when it is declared "dead". If the solar luminosity is 3.9 x 102 J s", and the masses of Hydrogen and Helium-4 nuclei are 1.0078 amu and 4.0026 amu, respectively, Estimate the "lifetime" (i.e., the duration of the above conversion) of the Sun in years. Calculate the rate of change of the solar mass due to the above fusion reaction