Mathematics

Even though it is a GK based blog, we are giving higher priority to getting a job. So we just familiarizing  some important Mathematics questions to freshers.

Mathematics has important role in all competitive exams. Even a single question can change your rank So  we are going to discuss some frequently asking maths questions in all competitive exams like IBPS, Bank Clerk, Postal Assistant, RRB and PSC. Adding more maths question is not so Practical in the case of our blog, so we are posting only One question from a category. Find more and practice regularly.


Some Important Maths Equations

1. a(b+c) = ab + ac

2. (a+b)2 = a2 + 2ab + b2

3. (a-b)2 = a2-2ab + b2

4. (a+b)2 = (a-b)2 + 4ab

5. (a-b)2 = (a+b)2 - 4ab

6. (a-b) (a+b) = a2 - b2

7. (a+b)3 = a3 + 3ab(a+b) + b3

8. (a-b)3 = a3 - 3ab(a-b) - b3

9. a3 + b 3 = (a+b) (a2 - ab + b2)

10. a3 - b 3 = (a-b) (a2 + ab + b2)

11. (a3 - b3) / (a2 + ab + b2) = a-b

12. (a3 + b3) / (a2 - ab + b2) = a+b
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How to use these equations in exams.

1. (4.75 x 4.75 x 4.75 + 1.25 x 1.25 x 1.25) / ( 4.75 x 4.75 + 1.25 x 1.25 - 4.75 x 1.25) = ?
If you saw a question like this, you can use these equations to find its answer. If try to solve these question without using equation you gonna take too much time , thats what the examiners want.

= (4.753 + 1.253) / (4.752 + 1.253 - 4.75 x 1.25)

now it is same like in the 12th equation (a3 + b3) / (a2 - ab + b2) = a+b

ie. = 4.75 + 1.25
 = 6 
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  Mathematics question from Train


1. A 250 m long train is running at a speed of 55 Km/hr. It crossed a platform of length 520 m in ? (Its a Previously asked on SSC 2012 exam) (*without a train question it is impossible to conduct an exam, I think you got, what I mean)

a) 40.4 sec                                           b) 40.5 sec

b) 50.4 sec                                           c) 50.5 sec


Speed = 55 Km/hr
(to convert km/hr in to M/s)
= 55 x 5/18 M/s

Distance = 250 m + 520 m ( If questions is about train crossing a post you need to consider only the length of Train, )

= 770 m

Time = Distance / Speed

= 770 x 18 / (5 x 55)

= 50.4 sec

Answer: b) 50.4 sec


Mathematics question from Work and Time


1. A can do a piece of work in 10 days and B alone can do it in 15 days. How much time will both take to finish the work ?

This question can be solved by different methods. We need to conserve time in exams so solving this problem using equations is the good idea.

Time taken to finish the job = XY / (X + Y)

= 10 x 15 / (10 + 15)

= 150 / 25

= 6 days


2. A and B together can do a piece of work in 10 days. B alone can finish it in 20 days. In how many days can A alone finish the work ?

 Time taken by A to finish the work = XY/(Y-X)

= 10 x 20 / (20-10)

=  200/10

= 20 days


Mathematics question from Simple & Compound Interest


1. Find the difference between the Simple Interest and Compound Interest for an amount of 50,000 at 10% of interest rate for 2 years ?

If you try to solve this problem without using Equation, You gonna spend too much time for this question.


Difference between SI and CI for 2 years = P (R/100)2

                                                                = 50000 x 10/100 x 10/100

                                                                = 500


Equation to find Difference between SI and CI for 3 years = P (R/100)2 ( 3 + R/100 ) Equation to find Difference between SI and CI for 4 years = P (R/100)2 ( 4 + R/100 )
Equation to find Difference between SI and CI for 5 years = P (R/100)2 ( 5 + R/100 )




Mathematics question from LCM & HCF


1. The LCM and HCF of two numbers are 8 and 48 respectively. If one of them is 24, Find the other ?

HCF x LCM = Product of Numbers

8 x 48 = 24 x the other number

other number = (8 x 48) / 24

other number = 16




 * Previously asked maths questions from numbers for competitive exams


1. Sum of two number = 16 and product = 48, find the difference of the two number ??


To solve this question, you can use the equation,

(X-Y)2  = (X+Y)2 - 4 XY

(X-Y)2 = (16)2 -  4 x 48

(X-Y)2 = 256 - 192

(X-Y)2 =  64

X-Y = 8

You can find one more maths question from this category here.. Solved maths question


* newly updated
More questions will be added soon. If you have any maths questions, please add it as comment.

53 comments :

  1. seriously?

    the whole god damn 2nd question from TIME and WORK is wrong.


    people who comment here, just comment BLINDLY?

    ReplyDelete
    Replies
    1. thank you very much.

      sorry for that god damn mistake.
      OMG, I can't believe no one find it earlier, or they just go without a word...

      thank you ...

      Delete
    2. its not wrong, there are different methods to solve, it is one of them

      Delete
    3. no its not wrong its absolutely right...shekhar u r correct

      Delete
    4. Actually it is not wrong u can verify from the Quikar maths by M.tyra

      Delete
    5. Now its not wrong, but when I published it, it was wrong, and Siddhant Priyadarshi done a good job by noting the error,

      thanks to all for your feedbacks

      Delete
  2. know perfectly then say what is wrong and right .how the 2nd time and work be wrong?it is right ?

    ReplyDelete
    Replies
    1. Ya, now its correct

      I corrected it....

      Delete
  3. rajdms.kumar@gmail.comJune 18, 2013 at 11:27 AM

    A refrigerator is sold at Rs. 9,200.00 on sale tax of 15% on list price. What is the list price of the refrigerator? (SSC cabinet secretariat pre exam held on 24.06.2013)

    ReplyDelete
    Replies
    1. 8000
      Its solved by me, so you should double check this answer !!!!!

      Thanks for the question.

      Delete
    2. Let, list price = Rs.x , So, sell price = x + x . 15% = 9200 & hence, x= Rs.8000

      Delete
  4. @rajdms. Since sales tax is applicable on List price so
    9600*(100-15)/100=96*85=8160

    ReplyDelete
    Replies
    1. this is the response from our facebook page

      Possible answers

      Delete
    2. Let us keep the list price as LP,then (LP*15/100)+LP=9200,By solving this we get 8000,So Hari is right..

      Delete
  5. very goood its help fulll for my maths exibution . iam very satisfied

    ReplyDelete
  6. i've got a no. of good pronlems for my math project.......thank you

    ReplyDelete
  7. A and B can do a piece of work in 18 days; B and C can do it in 24 days; A and C can do it in 36 days. In how many days will A,B,and C finish it,working together and separately? please sir give short cute method to solve this question....

    ReplyDelete
    Replies
    1. AB's one day work = 1/18 like that BC = 1/24 & AC = 1/36
      A+B+C's one day's work

      ie. AB+BC+AC = 1/18+1/24+1/36

      2(A+B+C)=by adding 1/18+1/24+1/36 we got 9/72

      A+B+C = 9/72*2

      A+B+C = 9/144

      dividing 9/144 we get

      A+B+C = 1/16

      A+B+C's one day work = 1/16

      A+B+C's together finish the work in 16 days (reciprocal of 1/16)

      Delete
  8. nyc answer n short to understand thnk admin

    ReplyDelete
  9. plz anser this qustn..1 person bring chapatis.all sleep 1 person weak up he divide all chapati in 3 set 1 set he eat and left 2 sets of chapati. 2nd and 3 rd person also do same things.at last all weak up eat same nos. of chapati then also 1 chapati extra so tell me how many chapaties they bring,,?

    ReplyDelete
  10. if amount of any value for 2 year is rs.3840/- & 3 years is Rs.4096/- then what will be the rate ?? please reply me on my mail:sohaanyadav@gmail.com

    ReplyDelete
  11. 01. In an examination, a student scores 4 marks for every correct answer and losses 1 mark for every wrong answer. a student attempted all the 200 questions and scored, in all 200 marks. The number of questions, he answered correctly was
    A. 82 , B. 80 , C. 68 , D. 60

    ReplyDelete
  12. 02. (0.1 x 0.01 x 0.001 x 10^7) is equal to
    A. 100 , B. 1/10 , C. 1/100 , D. 10

    ReplyDelete
  13. 1 st question for train convert to km/hr to m/s but how you can get the value i.e 5/18 please explain

    ReplyDelete
    Replies
    1. to convert km in to M = KM x 1000
      to convert hr in to s = Hr x 60 x 60

      so Km/ hr in to M / S = 1000/3600

      ie = 5/ 18

      In most cases the speed of the train given in multiple of 18, so using this method it can be solved in seconds.

      to convert m/s to Km/hr multiply with 18/5

      Delete
    2. Sir tell us some tricks of question based on percentages

      Delete
  14. pls giv online questions to solve

    ReplyDelete
  15. Question: i. Trains A and B are travelling on the same route heading towards the same destination. Train B has already covered a distance of 220km before the train A started.
    ii. The two trains meet each other after 11 hours after start of train A
    iii. Had the trains been travelling towards each other (from a distance of 220 km) they would have met after one hour.

    Question 1. What is the speed of trains 'B' in kmph?
    question 2: What is the speed of trains 'A' in kmph?

    how to solve this?

    ReplyDelete
    Replies
    1. speed of A is 120km/hr
      speed of B is 100km/hr

      Delete
    2. speed of A is 120km/hr
      speed of b is 100 km/hr

      Delete
  16. pls upload some computer awareness questions..

    ReplyDelete
  17. 50 after 0
    5 after e ,find the calculation and tell me any 1/cos c..........?

    ReplyDelete
  18. 50 after 0
    05 after e ? is the calaulation please tell 1/cos c

    ReplyDelete
  19. Awesome...... In my words keka...kevu keka.......

    ReplyDelete
  20. 2,3,4,4,6,8,9,12,16,?
    tell me plz how to solve it (ans. is 9).

    ReplyDelete

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