good one, however, it's already posted - check Sand-glass II.
there is more of this type in the section called Water and Weighing Puzzles
looking forward to new puzzles ... this thread is locked
to Emapher:
in your example you would travel (the whole way) 60 km in 80 minutes (the whole time) which is not the desired average speed of 60 km/hour
try using any other distance (which would not make the approximately 1 hour you mentioned) and see what happens
pls show me how you get the average speed 60 kph when you go half way at the speed of 30 kph ... choose any distance (some specific number in km), any total time (some specific number in hours - it does not have to be 1 hour - choose any) ... let's see if the average of 60 kph is possible
Interestingly enough, you've refuted your own point! I found this in the exact same article you provided.
So both parts of the man's statement must be true after all! I agree - only if he is an honestant.
editing is allowed only within 10 minutes to prevent unfair amendments ... only VIP members, moderator and I can edit their own posts without time limit
this is one of my favorites ... it is also the most repeated puzzle on this forum - still coming in new variations (stories) ... long discussion can be found in the thread entitled Honestants and Swindlecants III.
looking forward to new puzzles ... this topic is locked
wrong because:
If it were two hours later (10pm), it would be half as long until midnight (2 hours to midnight) as it would be if it were an hour later (at 9pm = remember your starting point is 8 pm = 3 hours to midnight which is not 2x2 hours).
I get your points theory and as mentioned - you would really have to exclude the time factor (which is the most important - it's all about the time)
the whole puzzle seemed so clear and simple to me ... until I posted it in this forum
I am missing your logic somehow ... let's say the distance from the starting point to the city is 60 km, then you say:
If half the distance (30 km) was traveled at 30 km/hr (so 1 hour) and the other half (remaining 30 km) of the distance traveled at 90 km/hr (so 20 minutes) ... then the average speed over that distance (60 km) is 60km/hr (60 km in 80 minutes ... so it's not 60 km in 60 minutes)