INFOSYS INTERVIEW QUESTIONS AND ANSWERS

I HAVE COLLECTED THESE QUESTIONS AND ANSWERS FROM THE MAILS IN THE GROUP ONLY. FOR 3-4 QUESTIONS ONLY I HAVE FOUND THE ANSWER WITH THE HELP OF MY TEACHERS. SO KEEP IN MIND THAT THESE ANSWERS MAY NOT BE 100% CORRECT. TRY TO SOLVE IT YOURSELF.

1. Youare given two candles of equal size, which can burn 1 hour each. You have

to measure 90 minutes with these candles. (There is no scale or clock). Also u r

given a lighter.

Ans: 1. First light up the two ends of the 1st candle. When it will burn out light up

one end of the second candle.(30+60=90)

2. Try the similar problem to measure 45 minutes.

Ans: First light-up the two ends of the 1st candle and one end of the 2nd candle.

When the 1st candle will burn out ,then light up the both ends of the 2ndcandle

(15+30=45)

3. You r given a thermometer. What can u do by this without measuring the

temperature?

Ans: if u put thermometer into a tree it won’t grow anymore, will just die off

OR

U r a landscape designer and your boss asked u to design a landscape such

that you should place 4 trees equidistance from each other.

(Distance from each tree to the other must be same)

Ans: Only 3 points can be equidistant from each other. But if u place points in the

shape of a pyramid then its possible

5. You are given a cake; one of its corner is broken. How will u cut the rest into

Two equal parts?

Ans: Slice the cake

6. How will you recognize the magnet & magnetic material & non-magnetic material?

Ans: Drag one piece of material over another. There is no attractive force in the

middle portion of the magnet.

OR

Get a piece of thread and tie up with the one bar and check for poles. If it iron bar

then it moves freely and if it is magnetic bar then it fix in one direction according to

poles.

7. If one tyre of a car suddenly gets stolen.... and after sometime u find the tyre

without the screws how will u make ur journey complete?

Ans: Open 3 screws, 1 from each tyre and fix the tyre.

8. How can u measure a room height using a thermometer?

Ans: temp varies with height. but its dependent on various other factors like

humidity, wind etc.

9. What is the height of room if after entering the room with a watch ur head

strikes a hanging bulb?

Ans: Oscillate the hanging bulb. Calculate the time period for one complete

oscillation by Simple Harmonic Motion (SHM) of the handing bulb. Put it in the

formula T=2 * 3.14 * (L/G)^1/2

L will be the length of the hanging thread.

Add the L with ur height to get the height of the room.

OR

Ans: Drop it from the room and find the time at which it strikes the floor. Using

physics formulas = (at^2)/2 (IM NOT SURE ABOUT THIS ONE)

10. Color of bear.... if it falls from 1m height in 1s.

Ans: We get 'g' perfect 10 which is only in poles...hence polar bear...color White

11. How will you measure height of building when you are at the top of the building?

And if you have stone with you.

Ans: Drop the stone and find the time taken for the stone to reach the ground. find

height using the formula

s = a + gt ( s = height, a= initial velocity=0, g=9.8m/s, t = time taken)

12. How wud u catch and receive a ball in same direction? (Dropping is from north

And receiving from bottom not accepted, as it is 2 directions)

Ans: ?

13. 25 statements given. Some tell truth, some false and some alternators. Find out

the true statements.

Ans: ?

14. Can u make 120 with 5 zeros?

Ans: Factorial (factorial (0)+factorial (0)+factorial (0)+factorial (0)+factorial (0)) =

120

15.There are three people A, B, C. Liars are of same type and Truth speaking people

are of same type. Find out who is speaking truth and who is speaking false from the

following statements:

a)A says: B is a liar.

b)B says: A and C are of same type.

Ans: lets assume A is speaking truth. It means B is a liar then it means A and C are

not of same type.

16.5 swimmers A, B, C, E, F and many conditions of their positions like there are

Two b/w A & F, B doesn't win etc the question was to find who was b/w like E & D?

Ans: ?

17. in a race u drove 1st lap with 40kmph and in the second lap at what speed u

must drive so that ur average speed must be 80kmph.

Ans: its impossible! if u drove the first lap in 40 kmph, its impossible that the

average speed of both the laps is 80kmph.

for eg. consider one lap distance = 80km.

time req. to cover 1 lap = 80km/40kmph = 2 hrs.

if the avg. speed is 80kmph, then the total time would have taken =

160kms/80kmph = 2 hrs.

same is the case with any other distance u consider. so the avg to be 80kmph is

impossible
18. You have to draw 3 concentric circles with a line passing thru their center

without lifting hand.

Ans: Start the line complete one circle move inside circles along the line and then

draw second circle. Like wise rest.

19. A rectangular paper is there. At a corner a rectangular size paper is taken from

it. Now you have to cut the remaining paper into two equal halves.

Ans: try it on the paper. You must fold the part that has complete paper and select

Half of it and then fold the part that cut and selects half of it and then cut along

the folding. (I DONT UNDERSTAND THIS ONE!!)

20. Value of (x-a)(x-b)………..(x-z)

Ans: 0 as there’s X-X term

21. There are 9 coins. 8 are of 1 gm and 1 is of 2 grams. How will you find out the

heavier coin in minimum number of weighing and how many weighing it will need?

Ans: 2 weighing ( Divide the number of coins into 3 parts at each weighing)

Aptitude Questions

1.One guy has Rs. 100/- in hand. He has to buy 100 balls. One football costs Rs. 15/, One Cricket ball costs Re. 1/- and one table tennis ball costs Rs. 0.25 He spend the whole Rs. 100/- to buy the balls. How many of each balls he bought?

2.The distance between Station Atena and Station Barcena is 90 miles. A train starts from Atena towards Barcena. A bird starts at the same time from Barcena straight towards the moving train. On reaching the train, it instantaneously turns back and returns to Barcena. The bird makes these journeys from Barcena to the train and back to Barcena continuously till the train reaches Barcena. The bird finally returns to Barcena and rests. Calculate the total distance in miles the bird travels in the following two cases:
(a) The bird flies at 90 miles per hour and the speed of the train is 60 miles per hour.
(b) the bird flies at 60 miles per hour and the speed of the train is 90 miles per hour

3.A tennis championship is played on a knock-out basis, i.e., a player is out of the tournament when he loses a match.
(a) How many players participate in the tournament if 15 matches are totally played?
(b) How many matches are played in the tournament if 50 players totally participate?

4.When I add 4 times my age 4 years from now to 5 times my age 5 years from now, I get 10 times my current age. How old will I be 3 years from now?

5.A rich merchant had collected many gold coins. He did not want anybody to know about them. One day, his wife asked, "How many gold coins do we have?" After pausing a moment, he replied, "Well! If I divide the coins into two unequal numbers, then 37 times the difference between the two numbers equals the difference between the squares of the two numbers." The wife looked puzzled. Can you help the merchant's wife by finding out how many gold R

6.A set of football matches is to be organized in a "round-robin" fashion, i.e., every participating team plays a match against every other team once and only once. If 21 matches are totally played, how many teams participated?

7.Glenn and Jason each have a collection of cricket balls. Glenn said that if Jason would give him 2 of his balls they would have an equal number; but, if Glenn would give Jason 2 of his balls, Jason would have 2 times as many balls as Glenn. How many balls does Jason have?

8.Suppose 8 monkeys take 8 minutes to eat 8 bananas.
(a) How many minutes would it take 3 monkeys to eat 3 bananas?
(b) How many monkeys would it take to eat 48 bananas in 48 minutes

9.It was vacation time, and so I decided to visit my cousin's home. What a grand time we had! In the mornings, we both would go for a jog. The evenings were spent on the tennis court. Tiring as these activities were, we could manage only one per day, i.e., either we went for a jog or played tennis each day. There were days when we felt lazy and stayed home all day long. Now, there were 12 mornings when we did nothing, 18 evenings when we stayed at home, and a total of 14 days when we jogged or played tennis. For how many days did I stay at my cousin's place?

10.A 31" x 31" square metal plate needs to be fixed by a carpenter on to a wooden board. The carpenter uses nails all along the edges of the square such that there are 32 nails on each side of the square. Each nail is at the same distance from the neighboring nails. How many nails does the carpenter use?

Answer and Explanation.

1. F + C + T = 100-------------eq1
15F + C + 0.25T = 100-------------eq2
eq1=eq2 .solve to get F=3T/56 ;F=3,T=56,C=41

2.a) There is no need to consider their meeting pt at all. the train has been running for 90miles/(60miles/hr)=1.5hrs.bird flies till train reaches destination frm strting pt. so bird flies for1.5hrs at the vel given(90).so dist=1.5*90=135miles

b) time of train=1hr. so dist of bird=60*1=60miles

3.(a) u don't need to sum it up. since it's a knock out only 1 person emerges winner finally.so15+1=16is answer. becos after15 matches finally we shud've 15losers and 1winner.

(b) 49:its always one less than no of players as per the idea given above. so no need to check okay cos its always true. ans is 49.

4. Let x= current age
4(x+4)+5(x+5)=10x ;so x=R 41 years

5.37(x-y)=x^2-y^2. u no tht x^2-y^2=(x-y)(x+y). so (x-y) cancels on both sides to give x+y=37. so sum of unequal halves=37 which is the req answer.

6.R ans:7 teams okay. for a match u need 2 teams. suppose there r totally 'n 'teams.
Now uve to choose 2 teams out of 'n' teams. so answer =no of such choices=no. of possible combinations. So we've ans = nC2(ncombination2)=21;solve to get n=7.
Sol: n(n-1)/2=21. so n=7.if u don't understand c the graph below
each team plays no. of matches=no of teams ahead of it. One bar '|' represents one team.
| | | | | | | ------------7
6 5 4 3 2 1 0 -----------21
last team is written as 0 matches becos this team has already played with all other teams-hence sum of matches =6+5+4+3+2+1=21 which is correct only if no of teams =7

7.R 14
1. G+2=j-2
2. 2(G-2)=J+2.
solve these 2 to get
J=14

8.a). Sol: each mky takes 8 min to eat a banana

b).ans:8m=48 m=6

9.Use sets and venn diagram to solve such questions. a, b, aub, anb etc.
12=tennis+leave
18=jog +leave
so jog-tennis=6
again jog+tennis=14.so solve and get jog=10,leave=8,tennis=4.so tot=22

10.Ans= 32*2 + 30*2=124