# Safety Fuses and Matches [duplicate]

You have 2 safety fuses and 4 matches. Each fuse takes exactly one hour to burn, but they are not perfect so may not necessarily burn evenly from both sides. For example, the first half might burn in 20 minutes and the second half might take 40 mins. but this does not change the total time to be burnt as stated.

How can you measure out 45 minutes by just using these two safety fuses and the matches you have?

• This is not a logic puzzle because it does not involve formal logical deduction. – Deusovi Feb 1 '16 at 14:06
• yes it is duplicate sorry about it... i could not find it when i look for it. – Oray Feb 1 '16 at 14:07

With the first fuse burning at both ends, it will take 30 minutes to burn completely. At this point, the second fuse will have 30 minutes remaining when burning at one end; lighting the other end will burn the rest of the second fuse in $30/2 = 15$ minutes. The total time taken is $30 + 15 = 45$ minutes.