Vipul was studying for his examinations and the lights went off. It was around 1:00 AM. He lighted two uniform candles of equal length but one thicker than the other. The thick candle is supposed to last six hours and the thin one two hours less. When he finally went to sleep, the thick candle was twice as long as the thin one. For how long did Vipul study in candle light?

vipul studied for 3 hrs....(consider both candels r of 12 inches(assume), thick one reduces 2 inces every hr n thin one 3 inches, so after 3 hrs thin will be 3 inches n thick one 6 inches)