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One evening there was a murder in the home of married couple, their son and daughter. One of these four people murdered one of the others. One of the members of the family witnessed the crime.The other one helped the murderer.
These are the things we know for sure:
1. The witness and the one who helped the murderer were not of the same sex.
2. The oldest person and the witness were not of the same sex.
3. The youngest person and the victim were not of the same sex.
4. The one who helped the murderer was older than the victim.
5. The father was the oldest member of the family.
6. The murderer was not the youngest member of the family.
Who was the murderer?
Find out the murderer here!
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What was the case?
From (6), we know the youngest one wasn't the murderer. Clue (3) suggests youngest wasn't the victim & (4) hints that youngest wasn't helper too. Hence, youngest must be witness.
So possibilities of others' role are listed in table below.
From (2), the witness had opposite sex than the oldest & from (5), we know father is the oldest. So witness must be daughter.
From (4), murderer was older than victim & since father is oldest he can't be victim. So last 2 possibilities are eliminated.
Mr. Rawat wishes to cross a the Sahara desert.
It requires 6 days to cross.
One man can only carry enough food and water for 4 days.
What is the fewest number of other men required to help carry enough food for Mr. Rawat to cross ?
He need only few helpers in the case!
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What's the challenge?
Mr. Rawat should take 2 helpers - let's name them as A & B.
Let 1 be the unit of food & water that is required for 1 day. So all are going to carry 4 units of food & water.
On the day 1, Mr. Rawat, B & A himself take the food & water from A. Then A will left with only 1 unit & to survive he should go back. In 1 day, he can consume that 1 unit of food & water & travel back to the origin.
On the day 2, Mr. Rawat & B consume 2 units food & water of helper B. Now helper B has to move back to origin with 2 units of food & water in 2 days. Again he can easily go back in 2 days covering distance traveled by him in 2 days of forward journey.
Now Mr. Rawat has 4 units of food & water which he can use in his 4 day's journey of crossing Sahara desert.
Lavesh, Bolt, and Lewis race each other in a 100 meters race. All of them run at a constant speed throughout the race.
Lavesh beats Bolt by 20 meters.
Bolt beats Lewis by 20 meters.
How many meters does Lavesh beat Lewis by ?
Know here the answer!
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What was the question?
Let Lavesh's speed be 10 m/s. Then he must have taken 10 seconds to finish the race. Since Bolt was beaten by Lavesh by 20 m he must have run 80m when Lavesh finished race in 10 seconds (t=10). So his speed would be 8 m/s.
Now Bolt requires 100/0.8 = 12.5 seconds to finish the race. When he finished, Lewis was 20m behind i.e. 80m from starting point at t = 12.5. So Lewis speed is 80/12.5 = 6.4 m/s
At t = 10 seconds, when Lavesh finished his race Lewis must be at 6.4 x 10 = 64 m from starting point. Hence Lavesh beats Lewis by 100 - 64 = 36 m.
Another method.
Let L be the speed of Lavesh, B be the speed of Bolt & W be that of Lewis. Then,
L/B = 100/80 = 5/4
L = (5/4) B .......(1)
Similarly,
B/W = 100/80 = 5/4
B = (5/4) W .......(2)
Putting (2) into (1),
L = (5/4) x (5/4) W
L/W = 25/16
L = (25/16) W
For given time t, when Lavesh finished the race,
Distance by L/ Distance by W = 25 / 16
100 m/ Distance by W = 25 / 16
Distance by W = (16 x 100) / 25 = 64.
So when Lavesh finished cross line at 100 m, Lewis was at 64m i.e. 36m behind. In other words, Lavesh beats Lewis by 100 - 64 = 36 m.
You are the ruler of a medieval empire and you are about to have a celebration tomorrow. The celebration is the most important party you have ever hosted. You've got 1000 bottles of wine you were planning to open for the celebration, but you find out that one of them is poisoned.
The poison exhibits no symptoms until death. Death occurs within ten to twenty hours after consuming even the minutest amount of poison.
You have over a thousand slaves at your disposal and just under 24 hours to determine which single bottle is poisoned.
You have a handful of prisoners about to be executed, and it would mar your celebration to have anyone else killed.
What is the smallest number of prisoners you must have to drink from the bottles to be absolutely sure to find the poisoned bottle within 24 hours?
Here is the test designed for it!
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