Aptitude Questions-1

Aptitude Questions -1 (culled from different IT company papers)

1.    A starts from a place at 11.00 a.m. and proceeds at a speed of 4 kmph. B starts at 1 p.m. with initial speed of 1 kmph and increases his speed every hour. At what time will B catch up with A?    

Answer: 9.48 p.m.

A starts at 11.00 a.m.                                                  B starts at 1.p.m.

@ 12 noon        A will be at 4 km                    B not yet started.

@  1.00 p.m.               “        8 km                   B just starts

@  2.00 p.m.               “       12 km                        B will be at 1 km

@  3.00 p.m.               “        16 km                       B       “        3 km ( B increases his

                                                                                                            Speed by 1 km)

@  4.00 p.m.               “        20 km                       B      “         6 km

Likewise

@  9.00 p.m.               “        40 km                       B      “        36 km

Hence between 9 and 10 p.m. B will catch A.  At 9 P.m. B ‘s speed was 8 kmph and between 9 p.m. and 10 p.m. his speed will be 9 kmph. A’s sped continues to remain at 4kmph.

So the relative speed between B and A at this time is 5 kmph. At 9.00 p.m. A is ahead of B by 4 km. Hence to catch up with him B will take  4 / 5 hours.

Ie 0.8 hours or 48 minutes. Hence B will catch up with A at 9.48 p.m.  

2.    Working independently Tina and Ann could finish a job in 12 hours and 9 hours respectively. If Tina works on the job independently for 8 hours and then Ann starts working independently on the same job, in how much time would Ann complete the job?

Answer: 3 hours.

Tina takes 12 hours to complete the job. In one hour she does 1/12 job and in 8 hours she had completed 8/12 = 2/3 job.

Hence remaining job is 1/3.

Ann takes 9 hours to complete a job. So, in one hour she does 1/9 job.

For completing th remaining 1/3 job she will take (1/3) / (1/9) = 3 hours.

3.    If a = 2, b = 4 and c = 5 then what is a + b / c  - c/a + b.

Answer: 11/30    This question had confused a few since the official answer was not tallying with their working.

Actually the question if looked at as (a + b) / c  -  c / (a + b) would give you the right answer.

4.    10^2 (10^8 + 10^8) =10^4 x ?   ( I have reframed the question so that there is no confusion in the mind of the students)

Answer: 2 * 10^6

10^2 * 2(10^8) = 2 * 10^2 x 10^8 = 2 * 10^10. Hence

2 * 10^10 = 10^4 x 2 * 10^6

5.    The maximum number of students among whom 1001 pens and 910 pencils can be distributed in such a way that each student get the same number of pens and pencils is:

Answer: 91  (Simple logic:  HCF of 1001 and 910 )

6.    The total population of a town was 8000. In one year the population increased by 9%.However, the Male population increased by 10% and the female population increased by 8%. How many males were there in the town initially?

Answer: 4000

Let the male population be x and female population be y. We know that x + y = 8000

Hence the female population y = 8000-x.

The men increases by 10% and the women increases by 8% and the total population increases by 9%.

So, we have an equation

x + 10x / 100 + (8000 – x) +8(8000-x)/100 = 8000 + 8000 x 9/100

Working out you will get the value of x as 4000.

7.    1000 boys and 800 girls took an examination. 60% of the boys an 50% of the girls passed the examination. What is he percentage of students who have not passed the examination?

Answer: 44.44%

Out of 1000 boys 60% passed ie 600 students. No. of boys failed 400

Out of   800 girls  50% passed ie 400 students. No. of girls  failed 400.

Total number of students failed is 800 out of total number students appeared 1800

Hence percentage of students failed is 800*100/1800 = 44.44%

8.    A company contracts to paint three houses. Mr Brown can paint a house in 6 days. Mr Black would take 8 days while Mr Blue will take 12 days to paint the house. Mr Brown starts the work and continues for 8 days and then leaves. Mr Black takes up the work, and works or 6 days and leaves. Now Mr Blue will be completing the contract in how many days?

Answer: 11 days.

Total job to be completed under the contract is 3 (houses)

Mr Brown in 1 day can do 1/6 job. So, in 8 days has done 8/6 or 4/3 job.

Mr Black in one day can do 1/8 job and in 6 days does 6/8 or ¾ job.

So Mr Brown and Mr Black together have completed 4/3 + ¾ = 25/12 job or 2 and 1/12 job. The remaining job is 11/12.

Mr Blue in one day can do 1/12 job and for completing the remaining 11/12 job would take 11 days.

9.    Two hours after a freight train leaves Delhi, a passenger train starts from the same station and in the same direction at a speed of 60 kmph. The passenger train overtakes the freight train in four hours. What is the speed of the freight train?

Answer: 40 kmph

 A simple sum. In 4 hours the passenger train would have travelled 4*60=240 kms

The freight train left 2 hours earlier than the passenger train. Hence to travel this distance of 240 kms, the freight train hd taken 2 + 4 = 6 hours.

Hence the speed of the freight train was 240 / 6 = 40 kmph.  

10.  A man fixed an appointment to meet the Manager. The Manager asked him to come two days after the day before the day after tomorrow. If today is Friday, then on what day the Manager fixed the appointment?

Answer: Monday. (Simple logic. Please note that this is a repeat question in many papers)

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 Aptitude Questions-1