Two candles of equal heights but different thickness are lighted. The first burns off in 2 hours and the second in 5 hours. How long after lighting the both, will the first candle be half the height of the second?
There is a cylindrical pen holder of height 10cm and diameter 13cm. Now the pen holder is cut into two pieces such that the height of the new pen holder is reduced to (35)th of the height. The diameter of the new pen holder remains the same. If the new pen holder is filled with water up to the brim, then find the amount of water held in liters. (Where π=3.14)