Aptitude Interview Questions

You are 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)

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

You are 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

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

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.

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.

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.

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.

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)

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.

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

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.

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.

Value of (x-a)(x-b). . . . (x-z)

Ans: 0 as there's X-X term

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)

If a bear walks one mile south, turns left and walks one mile to the east and then turns left again and walks one mile north and arrives at its original position, what is the color of the bear. 

ANS. The color of the bear is trivial. The possible solutions to it are interesting. In addition to the trivial north pole, there are additional circles near south pole. Think it out.

Given a rectangular (cuboidal for the puritans) cake with a rectangular piece removed (any size or orientation), how would you cut the remainder of the cake into two equal halves with one straight cut of a knife? 

ANS. Join the centers of the original and the removed rectangle. It works for cuboids too! BTW, I have been getting many questions asking why a horizontal slice across the middle will not do. Please note the "any size or orientation" in the question! Don't get boxed in by the way you cut your birthday cake :) Think out of the box.

You have 5 jars of pills. Each pill weighs 10 gram, except for contaminated pills contained in one jar, where each pill weighs 9 gm. Given a scale, how could you tell which jar had the contaminated pills in just one measurement? 

ANS. 1. Mark the jars with numbers 1, 2, 3, 4, and 5. 
2. Take 1 pill from jar 1, take 2 pills from jar 2, take 3 pills from jar 3, take 4 pills from jar 4 and take 5 pills from jar 5. 
3. Put all of them on the scale at once and take the measurement. 
4. Now, subtract the measurement from 150 ( 1*10 + 2*10 + 3*10 + 4*10 + 5*10) 
5. The result will give you the jar number which has contaminated pill.

In a tournament there are 20 flag poles equidistant from each other. each runner starts from the first flag. In 24 sec the runner reaches the 12th flag. How 
much it will take him to complete the 20th flag. 

ans. (24/11)*19

At 6'o clock clock ticks 6 times. The time between first and last ticks was 30sec. How much time it takes at 12'o clock. 

Ans. 66 sec. 2 marks.

Three friends divided some bullets equally. After all of them shot 4 bullets the total no. of remaining bullets is equal to that of one has after division. Find the original number divided. 

Ans. x x x 
x-4 x-4 x-4 
3x-12 = x 
x= 6 
ans is 18 2 marks

A ship went on a voyage after 180 miles a plane started with 10 times speed that of the ship. Find the distance when they meet from starting point. 

Ans. 180 + (x/10) = x 
x = 20 
ans is 180+20=200miles. 2 marks

There N stations on a railroad. After adding x stations 46 additional tickets have to be printed. Find N and X. 

Ans. let N(N-1) = t; 
(N+x)(N+x-1) = t+46; 
trail and error method x=2 and N=11 4 marks

A beggar collects cigarette stubs and makes one full cigarette with every 7 stubs. Once he gets 49 stubs . How many cigarettes can he smoke totally.

Ans. 8

1000000000 can be written as a product of two factors neither of them containing zeros

Ans 2 power 9 x 5 power 9

Light glows for every 13 seconds . How many times did it between 1:57:58 and 3:20:47 am

Ans : 383 + 1 = 384

A person spending out 1/3 for cloths , 1/5 of the remaining for food and 1/4 of the remaining for travelled is left with Rs 100/- . How he had in the beginning ?

Ans RS 250/