ARE YOU AWARE ABOUT THE BRAIN TEASERS ASKED IN BIG TECH COMPANIES IN SILICON VALLEY.
SO WE ARE GOING TO LOOK OVER THE BEST BRAIN TEASERS CHOSEN FORM THE BIGGEST TECH COMPANIES..AND ALSO YOUR DREAM COMPANY
SO LET'S GET STARTED
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A Russian gangster kidnaps you. He puts two bullets in consecutive order in an empty six-round revolver, spins it, points it at your head and shoots. *click* You’re still alive. He then asks you, “do you want me to spin it again and fire or pull the trigger again right away?” For each option, what is the probability that you’ll be shot?
Answer…
The key hint here is that the bullets were loaded adjacent to each other.
There are 4 ways to arrange the revolver with consecutive bullets so that the first shot is blank. These are the possible scenarios:
- (xBBxxx)
- (xxBBxx)
- (xxxBBx)
- (xxxxBB)
The other two scenarios would have meant you got shot on the first attempt. (BBxxxx) or (BxxxxB)
Now look at the second slot in those 4 possible scenarios above. Your odds of getting shot are 1/4 or 25%. (Only #1 would get you shot)
But if you respin… there are 2 bullets remaining and 6 total slots. 2/6 or 33%.
NICE ONE OK LET'S PROCEED TO THE NEXT ONE
You’re about to get on a plane to Seattle. You want to know if it’s raining. You call 3 random friends who live there and ask each if it’s raining. Each friend has a 2/3 chance of telling you the truth and a 1/3 chance of messing with you by lying. All 3 friends tell you that “Yes” it is raining. What is the probability that it’s actually raining in Seattle?
Answer…
You only need 1 of your friends to be telling the truth for it to be raining in Seattle.
It’s fastest just to calculate the odds that all 3 are lying, and it’s not raining.
Each friend has a 1/3 chance of lying. Multiply the odds together… you get 1/27 (1/3 * 1/3 * 1/3).
We’re not done yet though… 1/27 is the probability that all 3 friends lied at the same time.
The probability that at least 1 told you the truth? 26/27 or around a 96% that it’s raining in Seattle.
TOUGH BUT INTERESTING THOUGH
LET'S PROCEED TO ANOTHER SET OF BRAIN TEASERS ASKED BY
You have a 3 gallon jug and 5 gallon jug, how do you measure out exactly 4 gallons?
Answer…
We know we can’t get the final result in the 3 gallon jug. It’ll overflow. We need to end up with 4 gallons in the 5 gallon jug.
First fill the 3 gallon jug.
Then pour the 3 gallons into the 5 gallon jug.
Now the 3 gallon jug is empty, and the 5 gallon jug has 3 gallons in it.
Fill the 3 gallon jug again. Slowly pour into the 5 gallon jug. Only 2 gallons will fit because it already has 3. Now it’s full.
Exactly 1 gallon is left in the 3 gallon jug.
Dump out the 5 gallon jug.
Pour your 1 gallon into the 5 gallon jug.
Fill up the 3 gallon jug one more time and pour it into the 5 gallon jug! You have exactly 4 gallons (and possibly a job at Google)
IT WAS AN OP QUESTION ASKED BY GOOGLE
LET'S MOVE TO THE NEXT ONE
Why are manhole covers round?
Answer…
Good news: If you’re tired of math questions this one will give you a break.
Manhole covers are round because it’s the only shape that cannot fall through itself. The cover can never accidentally fall down the hole.
Microsoft has been known to ask this question and according to Glassdoor.com, Google is asking this too now.
ENJOYING??
LET'S PROCEED TO THE LAST SET OF BRAIN TEASERS ASKED BY
Apple
There are three boxes, one contains only apples, one contains only oranges, and one contains both apples and oranges. The boxes have been incorrectly labeled such that no label identifies the actual contents of its box. Opening just one box, and without looking in the box, you take out one piece of fruit. By looking at the fruit, how can you immediately label all of the boxes correctly?
Answer…
So, you know all 3 boxes are incorrectly labeled.
Go to the box labeled “Apples + Oranges.” Since the label is wrong, it must have one or the other.
This is the box to take one piece of fruit from. Whichever comes out is what that box contains. If you took out an apple, the box has only apples. If you took out an orange, vice versa.
Here’s where it gets tricky a bit tricky. But we’re almost done…
Let’s say you grabbed an apple. Move the “Apples” label over to that box. Now it’s correctly labeled.
You know the “Oranges” box is still labeled wrong (because all 3 were labeled wrong to start and you haven’t touched it). And you know it’s not “Apples”.
So it has to be “Apples + Oranges”.
The last box is “Oranges”.
The same process above would work if you had pulled out an orange at the start.
THE NEXT ONE IN 3...2...1..!!
You have 100 coins laying flat on a table, each with a head side and a tail side. 10 of them are heads up, 90 are tails up. You can’t feel, see or in any other way find out which 10 are heads up. Your goal: split the coins into two piles so there are the same number of heads-up coins in each pile.
Answer…
By pure coincidence… this is a trick my friend Mike showed me last summer. It blew my mind back then but hopefully it’ll make sense as I write it out.
You want an equal number of heads in each pile. There are currently 10 of them. You don’t know which but it doesn’t matter. All you have to do… take any 10 coins out of the 100, put them into a separate pile, and flip those 10 over.
That’s pile #1.
Pile #2 is the remaining 90 coins, unflipped. Just leave them.
You’re done. Seriously.
You can do this with any number of coins. If you had 20 coins, and 18 were heads, you’d need to take 18 of them (it doesn’t matter which) into a separate pile and flip those 18. That’s pile #1.
If you had 10 coins and 3 were heads, you’d take 3 random coins into a new pile and flip those 3 for your first pile, and the rest are your second pile.
Crazy right?
If you don’t believe me just grab some pennies and try it.
There are no exceptions and it doesn’t need to be an even amount of “heads” to begin with either. It can also be zero. Or all.
