Technical interview ques

1.             Question: Two old friends, Jack and Bill, meet after a long time.

Jack: Hey, how are you man?
Bill: Not bad, got married and I have three kids now.
Jack: That’s awesome. How old are they?
Bill: The product of their ages is 72 and the sum of their ages is the same as your birth date.
Jack: Cool… But I still don’t know.
Bill: My eldest kid just started taking piano lessons.
Jack: Oh now I get it.

How old are Bill’s kids?

Answer: Let’s break it down. The product of their ages is 72. So what are the possible choices?

2, 2, 18 – sum(2, 2, 18) = 22 & 2, 4, 9 – sum(2, 4, 9) = 15
2, 6, 6 – sum(2, 6, 6) = 14 & 2, 3, 12 – sum(2, 3, 12) = 17
3, 4, 6 – sum(3, 4, 6) = 13 & 3, 3, 8 – sum(3, 3, 8 ) = 14
1, 8, 9 – sum(1,8,9) = 18 & 1, 3, 24 – sum(1, 3, 24) = 28
1, 4, 18 – sum(1, 4, 18) = 23 & 1, 2, 36 – sum(1, 2, 36) = 39
1, 6, 12 – sum(1, 6, 12) = 19

The sum of their ages is the same as your birth date. That could be anything from 1 to 31 but the fact that Jack was unable to find out the ages, it means there are two or more combinations with the same sum. From the choices above, only two of them are possible now.

2, 6, 6 – sum(2, 6, 6) = 14
3, 3, 8 – sum(3, 3, 8 ) = 14

Since the eldest kid is taking piano lessons, we can eliminate combination 1 since there are two eldest ones. The answer is 3, 3 and 8.

  2.             Question: Four people need to cross a rickety bridge at night. Unfortunately, they have only one torch and the bridge is too dangerous to cross without one. The bridge is only strong enough to support two people at a time. Not all people take the same time to cross the bridge. Times for each person:  1 min, 2 mins, 7 mins and 10 mins. What is the shortest time needed for all four of them to cross the bridge?

Answer:  The fastest way to get 1 across and be back is to use 2 to usher 1 across. So let’s put all this together.

1 and 2 go cross
2 comes back
7 and 10 go across
1 comes back
1 and 2 go across (done)

Total time = 2 + 2 + 10 + 1 + 2 = 17 mins

Think smart

A police officer saw a truck driver clearly going the wrong way down a one-way street, but did not try to stop him. Why not?
Ans :  The truck driver was walking.



A woman gave natural birth to two sons who were born on the same hour of the same day of the same month of the same year. But they were not twins and she had no access to a time machine. How could this be?
Ans :  They were two of a set of triplets (or quadruplets, etc.)


A New York city hairdresser recently said that he would rather cut the hair of three Canadians than that of one New Yorker. Why?
Ans :  Because he would earn three times as much money!

simple things to know

A man fell off a smuggling boat into deep water. He could not swim and he was not wearing anything to keep him afloat. It took 30 minutes for the people on the boat to realize someone was missing. The missing man was rescued two hours later on the return trip. Why didn't he drown?
Ans:
       He fell into the Dead Sea, which lies between Israel and Jordan. The water is so salty and dense that anyone in it floats very easily. Note: the maximum depth of the dead sea is 1,237' (377 m) and smuggling boats are known to use the dead sea to transport goods.





Many shops have prices set just under a round figure, e.g. $9.99 instead of $10.00 or $99.95 instead of $100.00 . It is assumed that this is done because the price seems lower to the consumer. But this is not the reason the practice started. What was the original reason for this pricing method?

Ans:

        The practice originated to ensure that the clerk had to open the till and give change for each transaction, thus recording the sale and preventing him from pocketing the bank notes.

logical questions

1. Three men in a cafe order a meal the total cost of which is $15. They each contribute $5. The waiter takes the money to the chef who recognizes the three as friends and asks the waiter to return $5 to the men.

The waiter is not only poor at mathematics but dishonest and instead of going to the trouble of splitting the $5 between the three he simply gives them $1 each and pockets the remaining $2 for himself.

Now, each of the men effectively paid $4, the total paid is therefore $12. Add the $2 in the waiters pocket and this comes to $14.....where has the other $1 gone from the original $15?

Ans : Though the initial bill was $15 dollars, one of the five dollar notes gets changed into five ones. The total the three men ultimately paid is $12, as they get three ones back. So from the $12 the men paid, the owner receives $10 and the waiter receives the $2. $15 - $3 = $10 + $2

2.You are trapped in a room with two doors. One leads to certain death and the other leads to freedom. You don't know which is which.

There are two robots guarding the doors. They will let you choose one door but upon doing so you must go through it.

You can, however, ask one robot one question. The problem is one robot always tells the truth ,the other always lies and you don't know which is which.

What is the question you ask?

Ans : Ask one robot what the other robot would say, if it was asked which door was safe. Then go through the other door.

Explanation : If we are asking the ques to robot A, either of the robots should say lie which means,

(Lie) robot B saying door B is safe,then robot A will say door A is safe = door A is safe

(True) robot B saying door B is safe,then robot A will say door B is safe = door B is safe

Todays question

Answer is 6
The reason is, visit the numbers in rows from left to right.The central number equals half to the sum of the numbers in either side.So half of 9+3 is 6.



2.How many sides does a decagon have?
   Answer : 10
   Hint : Decade represents 10 years similarly decagon have 10 sides.