Problems on Time and Work asked in various placements

Time & Work:

Work = Men x Days

(M1 D1 T1 E1)/W1 = (M2 D2 T2 E2)/W2

Where M1, M2 = Men
            D1, D2 = Days
            T1, T2 = Time
            E1, E2 = Efficiency


1) 25 men complete a work in 25 days. In how many days one man do the same work?
a) 225
b) 625
c) 125
d) None

Ans: 625

2) A fisherman catch the 5 fishes in 5 days. In how many days 10 man catch 10 fishes?
a) 3
b) 4
c) 5
d) 6

Ans: 5

3) 40 men complete a work in 30 days. All men started work after every 10 days 5 men were left. In how many days the total work completed?
a) 4
b) 5
c) 6
d) 7

Ans: 6

4) 40 men complete a work in 150 days after 10 days 30 members join to them. In how many days the total work should be completed?
a) 20 days
b) 30 days
c) 40 days
d) 80 days

5) A Contract is to be completed in 46 days and 117 members set to work, each work in 8 hours, after 33 days 4/7 of the work is completed. How many additional may be employ. So that the work may be completed in time. Each man working 9 hours a day.
a) 81
b) 91
c) 27
d) 9

Ans: 81

6) 5 men (or) 9 women complete a work in 19 days. In how many days 3 men and 6 women complete the same work?
a) 10 days
b) 15 days
c) 20 days
d) 30 days

Ans: 15 days

Read More

Problems on Permutations and Combinations asked in various placements

1) In how many ways can the team members be arranged for the team picture if all the males are always together and if the team comprises of 7 males and 6 females?
  a) 13!
  b) 7! 7!
  c) 7! 6!
  d) 14!

2) A written exam consists of 6 questions with the answer options as yes/no/none. In how many ways can the examinees select the answers?
  a) 6P3 ways
  b) 6C3 ways
  c) 3C1. 3C1. 3C1. 3C1. 3C1
  d) (3C1)^6

3) In a quiz competition, the host asked a question provided three possible answers. What is the probability that the snswer choice which Rohit selects for a question is wrong?
  a) 1/3
  b) 1/2
  c) 3C1 * 3/2
  d) 2/3

4) Probability of one of the power plants over heating is 0.15per day and the probability of failure of the backup cooling system is 0.11. If these events are independent, what is the probability of "big trouble"(i.e. both events taking place)?
  a) 0.35
  b) 0.0185
  c) 0.0165
  d) 0.26

5) There are 5 letters and 5 addressed envelopes. The number of ways in which all the letters can be put in wrong envelope are?
  a) 119
  b) 44
  c) 59
  d) 40

6) Tickets numbered 1 to 20 are mixed up and then a ticket is drawn at random. what is the probability that selecting multiple of 3 or 5?
  a) 9/20
  b) 7/20
  c) 1/4
  d) None

7) A bag contains 2 red, 3 green and 2 blue, 2 balls are drawn at random. Probability that none of the balls drawn is blue?
a) 2/5
b) 10/21
c) 11/21
d) 9/21

8) Two dice are thrown simultaneously, what is the probability of getting two numbers whose product is even?
a) 1/4
b) 7/36
c) 3/4
d) none

9) From a pack of 52 cards, two cards are drawn together at random. What is the probability that both the cards are being kings?
a) 1/15
b) 25/37
c) 35/256
d) 1/221

10) In how many can a group of 5 men and 2 women be made out of a total of 7 men and 3 women?
a) 63
b) 62
c) 31
d) 30

11) A box contains 2 white balls, 3 black balls and 4 red balls. In how many ways can 3 balls be drawn from the box, if at least one black ball is to be included in the draw?
a) 32
b) 64
c) 33
d) 61

Read More

Problems on H.C.F and L.C.M asked in various placements

--> H.C.F = (H.C.F of Numerators)/(L.C.M of Denominators)

--> L.C.M = (L.C.M of Numerators)/(H.C.F of Denominators)

--> Two numbers are said to be co-primes. If their H.C.F is 1.

--> The product of Least powers of common prime factors gives H.C.F.

--> The product of highest powers of all the factors gives L.C.M


1) The LCM of 2⁶ x 3² x 5 x 7, 2³ x 3⁵ x 7 and 2 x 3⁴ x 5 is:
  a) 2⁶ x 3⁵
  b) 2⁶ x 3⁵ x 5
  c) 2⁶ x 3⁵ x 7
  d) 2⁶ x 3⁵ x 5 x 7

2) What is the LCM of 3, 2.7 and .09?
  a) 0.27
  b) 2.7
  c) 27
  d) 2700

3) Find the number to be multiplied by (-6)^(-1). so as to get (-8)^(-1) as the product?
  a) 3/4
  b) -(3/4)
  c) 4/3
  d) -(4/3)

4) What is the value of the expression 3√(√0.000729)?
  a) 0.03
  b) 0.3
  c) 3
  d) 0.27
  e) 0.027

5) What is the value of (3³ * 81² * 2⁰)/(9⁵)?
  a) 0
  b) 3
  c) 1/3
  d) None of the above

6) what is the H.C.F 2³ x 3² x 5 x 7⁴, 2² x 3⁵ x 5² x 7⁶ and 2³ x 5³ x 7²
  a) 980
  b) 840
  c) 740
  d) 540

Read More

Problems on Numbers(Aptitude) Questions asked in Various Campus Placements

Number:

               A Number is a group of digits.

Various types of Numbers:

1) Natural Numbers:

      1, 2, 3, 4, 5, 6, 7, 8, 9, 10................

These are called as Natural Numbers

2) Whole Numbers:

      0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10............

These are called as Whole Numbers

3) Integers:

............,-10, -9, -8, -7, -6, -5, -4, -3, -2, -1, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, ...............

These are called as Integers

Positive Integers(Natural Numbers): 1, 2, 3, 4, 5, 6, 7, 8, 9, 10.........

Negative Integers: -1, -2, -3, -4, -5, -6, -7, -8, -9, -10, ..............

Non-Negative Integers(Whole Numbers): 0, 1, 2, 3, 4, 5, 6, ...............

Even Numbers:  Numbers which are divisible by 2 are called as Even Numbers

Odd Numbers:  Numbers which are not divisible by 2 are called as Odd Numbers

Prime Numbers: If a number has exactly two factors called as prime number

Divisibility:

1)Divisible by 2: last digit is Even or not
       
         Eg: 1234 is divisible by 2
                1235 is not divisible by 2

2) Divisible by 3 and 9: Sum of digits

         Eg: 246591 = 2+4+6+5+9+1 = 27 which is divisible by 3 & 9
                1234 = 1+2+3+4 = 10 which is not divisible by 3 & 9

3) Divisible by 4: last two digits

         Eg: 5932  last two digits are 32, it is divisible by 4
                1435 last two digits are 35, it is not divisible by 4

4) Divisible by 8: last 3 digits

         Eg: 54352 last three digits are 352, it is divisible by 8
                576484 last three digits are 484, it is not divisible by 8

5) Divisible by 10: unit digit (or) last digit is 0
       
         Eg: 7849320, unit digit is 0, it is divisible by 10
                678405, unit digit is 5, it is not divisible by 10

6) Divisible by 11:

            (Sum of its digits at odd places) - (Sum of digits at Even Places)



Problems on Numbers:

1) What is the unit design in 7¹⁰⁵?
  a) 1
  b) 2
  c) 3
  d) 7

Show Answer

   7¹⁰⁵ = (7⁴)²⁶ x 7
   The Unit Digit of (7⁴)²⁶ is 1
   So, 7¹⁰⁵ = 1 x 7 = 7
   The Unit Digit of 7¹⁰⁵ is 7

2) 7589 - ? = 3434
  a) 4426
  b) 4706
  c) 4526
  d) 4155

Show Answer

   7589 - 3434 = ?
   4155=?
   So, Answer is 4155

3) 8988  ÷ 8 ÷ 4 = ?
  a) 280.75
  b) 280.50
  c) 280.20
  d) 280

Show Answer

4) How many of the following numbers is divisible by 132?

    264, 396, 462, 792, 968, 2178, 5184, 6336

  a) 4
  b) 5
  c) 6
  d) 7

Show Answer

   The factors of the 132 are 11, 3, 4
   264, 396, 792 and 6336 are divisible by 11, 3, 4
   So, Answer is 4.

5) Which one of the following number is exactly divisible by 11
  a) 235641
  b) 245642
  c) 315624
  d) 415624

Show Answer

   The Divisible condition for 11 is as follows
   (sum of digits at odd places) - (Sum of digits at even places)
   (4 + 5 + 2) - (1 + 6 + 4) = 11 - 11 = 0
   415624 is only divisible by 11.
   So, Answer is 415624

6) The difference of the squares of two consecutive odd integers is divisible by which of the following integers?
  a) 3
  b) 6
  c) 7
  d) 8

Show Answer

   Answer is 8

7) A number when divided by 296 leaves 75 as remainder. When the same number is divided by 37, the remainder will be?
  a) 3
  b) 1
  c) 5
  d) 8

Show Answer

   Answer is 1

8) How many natural numbers between 17 and 80 are divisible by 6?
  a) 5
  b) 6
  c) 7
  d) 11

Show Answer

   The Numbers which are divisible by 6 are as follows(from 18 to 78)
   18, 24, 30, 36,........ 79
   Let a=18, d=(24-18)=6, l=78=t_n
   t_n = a+(n-1)d
   78 = 18+(n-1)6
   (n-1)6 = 60
   n=11
   So, Answer is 11

9) What is the sum of (2+2²+2³+2⁴+...........+ 2¹⁰)?
  a) 2046
  b) 2048
  c) 1023
  d) 512

Show Answer

   Let a=2, r=2²/2=2, n=10
   sum = a(rⁿ-1)/(r-1)
   2(2¹⁰-1)/(2-1) = 2(1024 - 1) = 2046
   So, Answer is 2046

10)  What is the sum of whole numbers upto 100?
  a) 2050
  b) 5000
  c) 5050
  d) none

Show Answer

   So, Answer is 5050

11) which of the following numbers si divisible by 6?
  a) 4322
  b) 3142
  c) 2256
  d) 1640

12) Which number should be subtracted from 321 so that it becomes prime?
  a) 2
  b) 4
  c) 6
  d) 9

13) What is the value of (3³ * 81² * 2⁰)/(9⁵)?
  a) 0
  b) 3
  c) 1/3
  d) None of the above

14) Write 4.004 as a fraction of the lowest form
  a) 500/125
  b) 2002/500
  c) 1001/250
  d) 500/225

15) Find the number to be multiplied by (-6)^(-1). so as to get (-8)^(-1) as the product?
  a) 3/4
  b) -(3/4)
  c) 4/3
  d) -(4/3)

Thanks for Visiting.....

Read More