Aptitude Interview Questions

 Solution given below

1.A three digit number consists of 9,5 and one more number . When these digits are reversed and then subtracted from the original number the answer yielded will be consisting of the same digits arranged yet in a different order. What is the other digit?

2.A farmer built a fence around his 17 cows, in a square shaped region. He used 27 fence poles on each side of the square. How many poles did he need altogether?

3.On the first test of the semester, kiran scored a 60. On the last test of the semester, kiran scored   75%   By what percent did kiran's score improve?

4.A group consists of equal number of men and women. Of them 10% of men and 45% of  women are unemployed. If a person is randomly selected from the group. Find the probability for the selected person to be an employee.?

5. Randy's chain of used car dealership sold 16,400 cars in 1998. If the chain sold 15,744 cars in  1999,   by what percent did the number of cars sold decrease?

6. A radio when sold at a certain price gives a gain of 20%. What will be the gain percent, if sold for thrice the price?

A) 260%

B) 150%

C) 100%

D) 50%

E) None of these

 7). A zookeeper counted the heads of the animals in a zoo and found it to be 80. When he counted the legs of the animals he found it to be 260. If the zoo had either pigeons or horses, how many horses were there in the zoo?

8.If the Arithmetic mean is 34 and geometric mean is 16 then what is greates number in that series of numbers?

9. The diameter of the driving wheel of a bus is 140cm. How  many revolutions per minute must the wheel make in order to keep a speed of 66 kmph?

10. The boys and girls in a college are in the ratio 3:2. If 20% of the boys and 25% of the girls are adults, the percentage of students who are not adults is:??

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1)Ans

. Let the digit unknown be n.

       The given number is then  900+50+n=950+n.

       When reversed the new number is 100n+50+9=59+100n.

       Subtracting these two numbers we get 891-99n.

       The digit can be arranged in 3 ways or 6 ways.

       We have already investigated 2 of these ways.

       We can now try one of the remaining  4 ways. One of these is n 95

             100n+90+5=891-99n

             or    199n =796

             so, n=4

             the unknown digit is 4.

2) Ans.104 poles

                Here 25 poles Must be there on each side .And around four corners 4 poles will be      

        present. 4*25+4=100+4=104 poles.

3) Ans: 25%

      In first test kiran got 60

       In last test  he got 75.

       % increase in test  ( 60(x+100))/100=75

                                       0.6X+60=75

                                       0.6X=15

                                       X=15/0.6=25%

4)Ans:29/40

 Assume men=100,women=100 then employed men & women r (100-10)+(100-45)=145

So probability for the selected person to be an employee=145/200=29/40

5) Ans: 4%

Let  percentage of decrease is x , then

            16400(100-x)/100=15744

            16400-15744=164x

             x=656/164=4%

6) Ans: 260%

 Let  x be  original cost of  the radio.

       The solding price = (100+20)x=120x

       If , it is sold for thrice the price ,then 3*120x=360x

        So, gain percent is (360-100)=260%.

7) Ans 50

Let the number of horses = x
Then the number of pigeons = 80 – x.
Each pigeon has 2 legs and each horse has 4 legs.
Therefore, total number of legs = 4x + 2(80-x) = 260
=>4x + 160 – 2x = 260
=>2x = 100
=>x = 50.

8) Ans. 64

  Let two numbers be x, y;

         Arthmetic mean=34=>( x+y)/2=34

         x+y=68

         geometric mean=16=>(xy)pow 1/2=16

         xy=16*16=256

    By trail and error  16*16=64*4

             And 64+4/2=34

     So the greatest number it has series is 64.

9) Ans. 250

  Distance to be covered in 1 min=(66*1000)/60 m=1100m

        Circumference of the wheel =(2*22/7*0.70)m=4.4m.

        So, Number of revolutions per min=1100/4.4=250.

10) Ans.78%

 Suppose boys = 3x    and girls = 2x

        Not adults = (80*3x/100) + (75*2x/100) = 39x/10

        Required percentage = (39x/10)*(1/5x)*100 = 78%