national physical laboratory Recruitment Process, Interview Questions & Answers

Q: Consider a pile of Diamonds on a table. A thief enters and steals 1/2 of the total quantity and then again 2 extra from the remaining. After some time a second thief enters and steals 1/2 of the remaining+2. Then 3rd thief enters and steals 1/2 of the remaining+2. Then 4th thief enters and steals 1/2 of the remaining+2. When the 5th one enters he finds 1 diamond on the table. Find out the total no. of diamonds originally on the table before the 1st thief entered.

Q: There are 3 clans in an island - The Arcs who never lie, the Dons who always lie and the Slons who lie alternately with the truth. Once a tourist meets 2 guides who stress that the other is a Slon. They proceed on a tour and see a sports meet. The first guide says that the prizes have been won in the order Don, Arc, Slon. The other says that, the order is Slon, Don, Arc. (the order need not be exact). To which clan did each of the guides and the players belong? ...

Q: 3 policemen and 3 thieves had to cross a river using a small boat. Only two can use the boat for a trip. All the 3 policemen and only 1 thief knew to ride the boat. If 2 thieves and 1 policeman were left behind they would kill him. But none of them escaped from the policemen. How would they be able to cross the river?

Q: The citizens of planet nigiet are 8 fingered and have thus developed their decimal system in base 8. A certain street in nigiet contains 1000 (in base 8) buildings numbered 1 to 1000. How many 3s are used in numbering these buildings?

Q: At 6?o a clock ticks 6 times.The time between first and last ticks is 30 seconds.How long does it tick at 12?o clock?2.A hotel has 10 storey. Which floor is above the floor below the floor, below the floor above the floor, below the floor above the fifth.

Q: A long, long time ago, two Egyptian camel drivers were fighting for the hand of the daughter of the sheik of Abbudzjabbu. The sheik, who liked neither of these men to become the future husband of his daughter, came up with a clever plan: a race would dete

Q: There are 7 letters A,B,C,D,E,F,GAll are assigned some numbers from 1,2 to 7.B is in the middle if arranged as per the numbers.A is greater than G same as F is less than C.G comes earlier than E.Which is the fourth letter

Q: Jarius and Kylar are playing the game. If Jarius wins, then he wins twice as many games as Kylar. If Jarius loses, then Kylar wins as the same number of games that Jarius wins. How many do Jarius and Kylar play before this match?

Q: In a Park, N persons stand on the circumference of a circle at distinct points. Each possible pair of persons, not standing next to each other, sings a two-minute song ? one pair immediately after the other. If the total time taken for singing is 28 minutes, what is N?

Q: There are four dogs/ants/people at four corners of a square of unit distance. At the same instant all of them start running with unit speed towards the person on their clockwise direction and will always run towards that target. How long does it take for them to meet and where?

Q: Given a collection of points P in the plane , a 1-set is a point in P that can be separated from the rest by a line, .i.e the point lies on one side of the line while the others lie on the other side. The number of 1-sets of P is denoted by n1(P)....

Q: Consider a series in which 8 teams are participating. each team plays twice with all other teams. 4 of them will go to the semi final. How many matches should a team win, so that it will ensure that it will go to semi finals.?

Q: Jack and his wife went to a party where four other married couples were present. Every person shook hands with everyone he or she was not acquainted with. When the handshaking was over, Jack asked everyone, including his own wife, how many hands they shook?

Q: Joe started from Bombay towards Pune and her friend julie in opposite direction. they met at a point . distance traveled by joe was 1.8 miles more than that of julie.after spending some both started there way. joe reaches in 2 hours while julie in 3.5 hours.Assuming both were traveling with constant speed. What is the distance between the two cities.

Q: There are some chickens in a poultry. They are fed with corn. One sack of corn will come for 9 days. The farmer decides to sell some chickens and wanted to hold 12 chicken with him. He cuts the feed by 10% and sack of corn comes for 30...

Q: Motorboat A leaves shore P as B leaves Q; they move across the lake at a constant speed. They meet first time 600 yards from P. Each returns from the opposite shore without halting, and they meet 200 yards from. How long is the lake?

Q: In mathematics country 1,2,3,4....,8,9 are nine cities. Cities which form a no. that is divisible by 3 are connected by air planes. (e.g. cities 1 & 2 form no. 12 which divisible by 3 then 1 is connected to city 2). Find the total no. of ways you can go to 8 if you are allowed to break the journeys.

Q: Six persons A,B,C,D,E & F went to solider cinema. There are six consecutive seats. A sits in one of the seats followed by B, followed by C and soon. If a taken one of the six seats , then B should sit adjacent to A. C should sit adjacent A or B. D should sit adjacent to A, B,or C and soon. How many possibilities are there?

Q: Two unemployed young men decided to start a business together. They pooled in their savings, which came to Rs. 2,000. They were both lucky, their business prospered and they were able to increase their capital by 50 per cent every three years. How much did they have in all at the end of eighteen years?

Q: There are 100 people in an organization. If 46 people can speak English, 46 Spanish, 58 French, 16 can speak both English and Spanish, 24 can speak both Spanish and French, 26 both English and French and 7 can speak all the languages.How many are there who cannot speak any of the three languages.