How many points are there on the globe where, by walking one mile south, then one mile east and then one mile north, you would reach the place where you started?
There are hundred red gems and hundred blue gems. The blue gems are priceless while the red gems equal wastage. You have two sacks one labeled Heads and the other Tails. You have to distribute the gems as you want in the two sacks. Then a coin will be flipped and you will be asked to pick up a gem randomly from the corresponding sacks.
How will you distribute the gems between the sacks so that the odds of picking a Blue gem are maximum?
A mile-long train is moving at sixty miles an hour when it reaches a mile-long tunnel. How long does it take the entire train to pass through the tunnel?