Three lions and three antelope are stranded on the east bank of a river and need to reach the west. A raft is available, which can carry a maximum of two animals at a time and needs at least one animal on-board to row it across (assume the animals can row). If the lions ever outnumber the antelope on either side of the river (including the animals in the boat if it's on that side), the lions will eat the antelope.
Given these rules, how can all the animals make the crossing and survive? Each step of an escalator is 8 inches taller than the previous step. The total vertical height of the escalator is 20 feet. The escalator moves upward one half step per second. If I step on the lowest step at the moment it is level with the lower floor, and run up at a rate of one step per second, how many steps do I take to reach the upper floor? (Note: Do not include the steps taken to step on and off the escalator.)
In the green-eyed logic puzzle, there is an island of 100 perfectly logical prisoners who have green eyes—but they don't know that. They have been trapped on the island since birth, have never seen a mirror, and have never discussed their eye color.
On the island, green-eyed people are allowed to leave, but only if they go alone, at night, to a guard booth, where the guard will examine eye color and either let the person go (green eyes) or throw them in the volcano (non-green eyes). The people don't know their own eye color; they can never discuss or learn their own eye color; they can only leave at night; and they are given only a single hint when someone from the outside visits the island. That's a tough life! One day, a visitor comes to the island. The visitor tells the prisoners: "At least one of you has green eyes." On the 100th morning after, all the prisoners are gone, all having asked to leave on the night before. How did they figure it out? A fisherman has a pond with six fish in one corner, a third as many in another corner, twice as many in a third corner, and five in the fourth corner. While ushering the fish together to the center of the pond, the fisherman let one of the fish groups get scattered all over the pond. How many fish groups did the fisherman end up with?
I had a wad of money in my pocket. I gave half away and of what remained, I spent half. Then, I lost five dollars. That left me with just five bucks. How much money did I start with?
A hiker comes across an intersection where three roads cross. He looks for the sign indicating the direction to his destination city. He finds that the pole carrying three city names and arrows pointing to them has fallen. He picks it up, considers it, and pops it back into place, pointing out the correct direction for his destination. How did he do it?
A slippery sloth climbs six feet up a utility pole during the day, then slides back down five feet during the night. If the pole is 30 feet high and the sloth starts from the ground (zero feet), how many days does it take the sloth to reach the top of the pole?
Place the digits 1-9 in the empty white squares so that the 3 horizontal and 3 vertical equations are true. Each digit will be used exactly once. Calculations are done from left to right and from top to bottom.
Place the digits 1-9 in the empty white squares so that the 3 horizontal and 3 vertical equations are true. Each digit will be used exactly once. Calculations are done from left to right and from top to bottom.
In city A in the desert, there is a man with his camel and 1000 watermelons. He wants to sell the watermelons in city B where a fair takes place. The distance between city A and B is 99 km.
However, the camel can only carry a maximum of 100 watermelons at a time. In addition to that, the camel eats one watermelon per kilometer it travels. The man wants to bring as many watermelons to the fair as possible. How can he do it? And what is the maximum number he can take? Hint: What if the distance was just 1 km? What if it was 2 km? What if it was 5 km? |