Thursday, November 17, 2011

Infosys Puzzles -1 – Placement papers, Interview Questions & Tutorials
Infosys Puzzles
1.There is a escalator and 2 persons move down it.A takes 50 steps and B takes 75 steps
while the escalator is moving down. Given that the time taken by A to take 1 step is
equal to time taken by B to take 3 steps. Find the no. of steps in the escalator while it is
Solution (not sure):
If A takes 1 step in one second, then B takes 3 steps in one second. If A takes t1 seconds
to take 50 steps, then B takes 150 steps in t1 seconds.
For B, to take 150 steps he requires t1 seconds,
then to take 75 steps he requires t1/2 seconds.
So now, s1=50, t1 = t1 & s2=75, t2=t1/2
ans= (s1*t2 ~ s2*t1) / (t1 ~ t2) which gives 100.
so 100 steps is the answer

2. If 5/2 artists make 5/2 paintings using 5/2 canvases in 5/2 days then how many artists
r required to make 25 paintings using 25 canvases in 25 days?

3. If the digits of my present age are reversed then i get the age of my son.If 1 year ago
my age was twice as that of my son.Find my present age.
ans. father-73, son-37

4. There are 6561 balls out of them 1 is heavy.Find the min. no. of times the balls have
to be weighed for finding out the haevy ball.
ans. 8

5. If i walk with 30 miles/hr i reach 1 hour before and if i walk with 20 miles/hr i reach 1
hour late.Find the distance between 2 points and the exact time of reaching destination
is 11 am then find the speed with which it walks.
ans. 120miles and 24 miles/hr
6. There r four face cards (J,Q,K,A) all of different types(diamond,club,spade,heart) and
some conditions r given.find the order of cards
ans. king -> jack -> queen -> ace
heart diamond spade club
7. If A,B,C,D,E r 5 members of a family.4 of them give true statements :
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1. E is my mother in law
2. C is my son in law's brother
3. B is my father's brother
4. A is my brother's wife
Who made the stmt. and what r the realtions among them
ans. E
<--> denotes husband-wife
-- denotes brothers
8. The product of 5 different temperatures is 12.If all of then r integers then find all the
ans. -2,-1,1,2,3
9.There r 9 cities numbered 1 to 9.From how many cities the flight can start so as to
reach the city 8 either directly or indirectly such the path formed is divisible by 3.
eg. 1368-Flights goes through 1-3-6-8.
10. If i do this puzzle i find it to be hard than the last puzzle that i did before that after
that..............very complex stmt.
Is that puzzle difficult,easy,can't say or depends on the no. of puzzles
11. Replace each letter by a digit. Each letter must be represented by the same digit and
no beginning letter of a word can be 0.
Ans: 0 =1, N = 8 ,E = 2, T = 7.

12. Ann, Boobie, Cathy and Dave are at their monthly business meeting. Their
occupations are author, biologist, chemist and doctor, but not necessarily in that order.
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Dave just told the biologist that Cathy was on her way with doughnuts. Ann is sitting
across from the doctor and next to the chemist. The doctor was thinking that Boobie
was a goofy name for parent's to choose,but didn't say anything. What is each person's
Ans: Since Dave spoke to the biologist and Ann sat next to the chemist and across the
doctor, Cathy must be the author and Ann the biologist. The doctor didn't speak, but
David did, so Bobbie is the doctor and Dave the chemist.

13. Sometime after 10:00 PM a murder took place. A witness claimed that the clock
must have stopped at the time of the shooting. It was later found that the postion of
both the hands were the same but their positions had interchanged. Tell the time of the
shooting (both actual and claimed).
Ans: Time of shooting = 11:54 PM Claimed Time = 10:59 PM.

14. Next number in the series is 1 , 2 , 4 , 13 , 31 , 112 , ?
Ans: 224.
No number has digits more than 4. All of them are 1 , 2, 4, 8 , 16 , 32 , 64 converted to
numbers in base 5.

15. Shahrukh speaks truth only in the morning and lies in the afternoon, whereas
Salman speaks truth only in the afternoon. A says that B is Shahrukh. Is it morning or
afternoon and who is A - Shahrukh or Salman?
Ans: Afternoon.A is Salman.

16. Two trains starting at same time, one from Bangalore to Mysore and other in
opposite direction arrive at their destination 1 hr and 4 hours respectively after passing
each other. How nuch faster is one train from other?
Ans: Twice.

17. There are 6 volumes of books on a rack kept in order ( ie vol.1, vol. 2 and so on ).
Give the position after the following changes were noticed. All books have been
changed Vol.5 was directly to the right of Vol.2 Vol.4 has Vol.6 to its left and both
weren't at Vol.3's place.Vol.1 has Vol.3 on right and Vol.5 on left. An even numbered
volume is at Vol.5's place Find the order in which the books are kept now.
Ans: 2, 5,1,3,6,4.
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18. I bought a car with a peculiar 5 digit numbered licence plate which on reversing
could still be read. On reversing value is increased by 78633.Whats the original number
if all digits were different?
Ans: Only 0 1 6 8 and 9 can be read upside down. So on rearranging these digits, we get
the answer as 10968.

19. The shape in the sketch below is that of a square attached to half of a similar square.
Divide it into four equal pieces.
Ans: Hint : The figure can be divided into 12 equal triangles.

20) There are two balls touching each other circumferencically. The radius of the big ball
is 4 times the diameter of the small all. The outer small ball rotates in anticlockwise
direction circumferencically over the bigger one at the rate of 16 rev/sec. The bigger
wheel also rotates anticlockwise at N rev/sec. What is 'N' for the horizontal line from the
centre of small wheel always is horizontal.

Q) Strike off any digit from each number in seven rows (need not be at same place) and
combine the same operations with 3 digit numbers to get the same addition. After this
strike off another digit from all and add all the No.s to get the same 2 digit No. perform
the same process again with 1 digit No.s. Give the ' no.s in 7 rows at each stage.

22) There is a safe with a 5 digit No. The 4th digit is 4 greater thansecond digit, while 3rd
digit is 3 less than 2nd digit. The 1st digit is thrice the last digit. There are 3 pairs whose
sum is 11. Find the number.
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Ans: 65292.

23) there are 2 guards Bal and Pal walking on the side of a wall of a wearhouse(12m X
11m) in opposite directions. They meet at a point and Bal says to Pal "See you again in
the other side". After a few moments of walking Bal decides to go back for a smoke but
he changes his direction again to his previous one after 10 minutes of walking in the
other(opposite) direction remembering that Pal will be waiting for to meet. If Bal and
Pal walk 8 and 11 feet respectively, how much distance they would have travelled
before meeting again.

24. 13 kigs and 6 libs can produce 510 tors in 10 hrs, 8 kigs and 14 libs can produce 484
tors in 12 hrs.
Find the rate of production of tors for kigs and libs. Express the answer in tors/hr.

Q) Find the 5 digit No.
Hint: 5 is used atleast once in the calculation.
26) A fly is there 1 feet below the ceiling right across a wall length is 30m at equal
distance from both the ends. There is a spider 1 feet above floor right across the long
wall eqidistant from both the ends. If the width of the room is 12m and 12m, what
distance is to be travelled by the spider to catch the fly, if it takes the shortest path.

27) Ramesh sit around a round table with some other men. He has one rupee more than
his right person and this person in turn has 1 rupee more than the person to his right
and so on, Ramesh decided to give 1 rupee to his right & he in turn 2 rupees to his right
and 3 rupees to his right & so on. This process went on till a person has 'no money' to
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give to his right. At this time he has 4 times the money to his right person. How many
men are there along with Ramesh and what is the money with poorest fellow.

28)Question related to probabilities of removing the red ball from a basket, given that
two balls are removed from the basket and the other ball is red. The basket contains
blue,red,yellow balls.

29)Venkat has 1boy&2daughters.The product of these children age is 72.The sum of
their ages give the door numberof Venkat.Boy is elder of three.Can you tell the ages of
all the three.

30)L:says all of my other 4 friends have money
M:says that P said that exact one has money
N:says that L said that precisely two have money
O:says that M said that 3 of others have money.
P:Land N said that they have money.


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