if u have two candles.. a single candle burns completely in 60 mins..
you have to calculate 90 minutes with the help of candles....
you are provided with a lighter and nothing else...how will u calcuate 90 minutes.

• One candle normally which will be 60 minutes. The other one should be burnt from both the sides together which will give 30 minutes.
• 10 years agoHelpfull: Yes(2) No(0)
• Firstly first will burn in 60 mins and after 60 min burn second candle from both its top and bottom ,it will give 30 mins.So,this way we can calculate 90 mins
• 10 years agoHelpfull: Yes(1) No(0)
• we burn 1st candle from one end, when it burns completly, it means 60 mins are over. Then after burn 2nd candle from both ends,after 30mins it will burn completely, in this way one can count 90 mins.
• 10 years agoHelpfull: Yes(1) No(0)
• i shall lighting up a candle from both side,and the other one from single side,just after the end of the first one.so the totaltime taken by two candle will be 9o min
  
• 10 years agoHelpfull: Yes(1) No(0)