The sun is daily burning itself to generated light for the human life. It converts 4.3 million ton of matter into energy every second. 75% of this mass is hydrogen while only 12.5% of these hydrogen molecules is in the core and is able to take part in nuclear fusion. The efficiency of the reaction is only 0.73% and is being released as energy in the chain reaction. Make an assumption that the total mass of the sun nowadays is 2x1030kg, how long is the lifetime of the sun.