You are presented with 2 fuses (lengths of string) each of which will burn for exactly 1 minute, but not uniformly along its length. Can you use them to measure 45 seconds?
2007-01-31 18:21:15 · 5 answers · asked by Joanna U 1 in Science & Mathematics ➔ Mathematics
Initially burn 1st fuse from both side and 2nd fuse from only one side
Now, after 30 seconds 1st fuse will burn completely . now, at this moment burn 2nd fuse from other side also..so it will finish at 45 second
2007-01-31 18:50:11 · answer #1 · answered by Pradeep Chelani 2 · 2⤊ 1⤋
mark the strings at their 3/4 length-point because since each string burns exactly for 1 minute, 3/4 of a minute = 45 secs, 3/4 of the string is 45 seconds. Is it?
2007-01-31 18:31:44 · answer #2 · answered by Gaara of the Sand 3 · 0⤊ 1⤋
Cross the fuses so that one fuse is perpedicular to the other at 3/4 of its length.
2007-01-31 18:30:58 · answer #3 · answered by Aldo 5 · 0⤊ 1⤋
no
If the fuses burned at a uniform rate then you could find 45 secs with one fuse
Fold it in half, then half again to find 1/4 of its length
then cut off that 1/4
that will take 45secs to burn
if they do not burn steadily then I dont know how you would use them
sorry
2007-01-31 18:31:05 · answer #4 · answered by brainiac 4 · 0⤊ 1⤋
uh...no. =D
2007-01-31 18:25:07 · answer #5 · answered by eriq p 4 · 0⤊ 1⤋