A secret can be told only 2 persons in 5 minutes .the
same person tells to 2 more persons and so on . How long
will take to tell it to 768 persons ?

Answers were Sorted based on User's Feedback



A secret can be told only 2 persons in 5 minutes .the same person tells to 2 more persons and so o..

Answer / harry

5 min-2
10-4
15-8
20-16
25-32
30-64
35-128
40-256
45-512
47.5-768

r u clear friends..

Is This Answer Correct ?    257 Yes 22 No

A secret can be told only 2 persons in 5 minutes .the same person tells to 2 more persons and so o..

Answer / sourav

47.5

Is This Answer Correct ?    95 Yes 12 No

A secret can be told only 2 persons in 5 minutes .the same person tells to 2 more persons and so o..

Answer / jyoti chandra azad

47.5 mins
because 2^9=512
& 2^10=1024 but
total no. of persons=768
i.e 512+256(or 2^8)
so for 9th iteration it is 9*5=45mins
but after that only half persons(512/2=256) are to be
informed which will take 2.5mins(5/2). so
the final answer will be 45+2.5=47.5 mins....

Is This Answer Correct ?    46 Yes 9 No

A secret can be told only 2 persons in 5 minutes .the same person tells to 2 more persons and so o..

Answer / rajez

no way,wat a que?
nice ques
Ans is 47.5.Its sure.

Is This Answer Correct ?    25 Yes 8 No

A secret can be told only 2 persons in 5 minutes .the same person tells to 2 more persons and so o..

Answer / laughing man

First in an aptitude question students are expected to keep
their eyes open to the terms used in the question. Otherwise
an aptitude paper would be the same as that of a 6th or 7th
standard question paper. The original question here was "the
same person". So the same person tells it to different
couple of people taking 5 mins each. 768 person here, so
768/2=384,384*5=1920 should have been the answer.

Now, supposing its a typical maths question, i.e. assuming
all the above assumptions made in the earlier posted answers
to be true, its a simple GP series which starts from 1, then
2 then 4 then 8 and so on.

So, by the problem,
2^0 + 2^1 + 2^2 +....+ 2^n = 768 (note: the first person has
been counted in the series)

so putting the summation formula for GP
1.(2^(n+1)-1) / (2-1) = 768
=> 2^(n+1) = 769
Now, 2^9 = 512 (leaving 257 behind)
Again, the count of 5 mins will be n number of times cause
the first term, i.e. 2^0 is the first person and he already
knows the secret, so the count will start essentially after
him. So n+1=9 => n=8. And for the remaining 257(actually
256, as the first person is counted in it) will be told in
extra 2.5 mins. So total, 8*5 + 2.5 = 42.5

Is This Answer Correct ?    5 Yes 4 No

A secret can be told only 2 persons in 5 minutes .the same person tells to 2 more persons and so o..

Answer / krishna

1 person told 2 persons in 5 min
so these 3 will tell 6 persons in 10min
3-6-10min
9-18-15min
27-54-20min
81-162-25min
243-486-30min
so 243+486=729 people know the secret
768-729=39
these 39 people will get to know in another 5 mins so 35 is the ans

Is This Answer Correct ?    0 Yes 0 No

A secret can be told only 2 persons in 5 minutes .the same person tells to 2 more persons and so o..

Answer / crazyfantaxy

i don't understand, why are you ppl not counting the ppl who
have been told the secret before

5 min-2
10-4, total so far=6
15-8, total so far=14
20-16, tsf=30
25-32, tsf=62
30-64, tsf=126
35-128, tsf=254
40-256, tsf=510
45-512, tsf=1022
---------------
50-1024, tsf=xyz

clearly ans should lie between 40 & 45...the options
definitely do not include the correct one!

you can also solve it by using binary tree + GP + log and
find the ans to be around 43

Is This Answer Correct ?    12 Yes 13 No

A secret can be told only 2 persons in 5 minutes .the same person tells to 2 more persons and so o..

Answer / guest

47.5mins

Is This Answer Correct ?    10 Yes 11 No

A secret can be told only 2 persons in 5 minutes .the same person tells to 2 more persons and so o..

Answer / honey goel

45 is the corrct one...many answers above r not counting the persons who hav been told earlier!!

Is This Answer Correct ?    0 Yes 1 No

A secret can be told only 2 persons in 5 minutes .the same person tells to 2 more persons and so o..

Answer / vikas kumar

haramzado gandh payya hua hai
khud to wrong kiya hai dusro ko bhi bakwaas sikha rahe ho

5 min-2 1 slot
10-4 2nd slot
15-8 3rd slot
20-16 4th slot
25-32 5th slot
30-64 6th slot
35-128 7th slot
40-256 8th slot

till now total people knowing secret is
1+2+4+8+16+32+64+128+256=511(approxx) heee..


for next 5 min all 256 people will be telling crap secret to
their next 2 people each.so in 5 minutes
we will have 768 people.time required will be same either
we need 257 people or 512 i.e 5minutes

so

40min + 5 min = 45 minutes.

vkx

Is This Answer Correct ?    1 Yes 2 No

Post New Answer

More General Aptitude Interview Questions

A person has Rs 100/- in his pocket, he can as 25 pencils or 15books. He kept 15% of the money for travelling expenses and purchased 5 ncils.So how many books he can purchase with the remaining money.

0 Answers   IBM,


The commerce minister of India IS?

1 Answers   JP Group,


hockey asia cup tournament held in 2007 was won by

2 Answers   State Bank Of India SBI,


In 1991, was the number of people in City A three times greater then the number of people in City B? 1) In 1991, there were approximately 1.1 million more people in City A than in City B. 2) In 1991, the 300,000 Catholics in City A made up 20% of its population, and the 141,000 Buddhists in City B made up 30% of its population. a) if statement (1) ALONE is sufficient, but statement (2) alone is not sufficient to answer the question. b) if statement (2) ALONE is sufficient, but statement (1) alone is not sufficient to answer the question. c) if BOTH statements (1) and (2) TOGETHER are sufficient to answer the question asked, but NEITHER statement ALONE is sufficient. d) if EACH statement ALONE is sufficient to answer the question asked. e) if statements (1) and (2) TOGETHER are NOT sufficient to answer the question asked, and additional data specific to the problem are needed.

0 Answers   Accenture,


There is a 14 digit credit card number in which every 3 consecutive digits add to 20. Here is a part of it.. Find the value of 'x'? _ _ _ 9 _ _ _ x _ _ _ 7 _ _

0 Answers   Accenture,






0, 7, 26, 63, 124, __

4 Answers   Geometric Software, Godrej, Infosys,


There are 5 burglars and once went to a bakery to rob it obviously The first guy ate 1/2 of the total bread and 1/2 of the bread. The second guy ate 1/2 of the remaining and 1/2 of the bread. The third guy ,fourth guy and fifth guy did the same. After fifth guy there is no bread left out. How many bread are there?

6 Answers  


Perimeter of front wheel =30, back wheel = 20. If front wheel revolves 240 times. How many revolutions will the back wheel take?

4 Answers   3i Infotech, Canara Bank, Geodesic,


A box consists of 12 poles and 7 pices of nets totally weighing 1.75pounds. If each pole weighs .07 pound and each piece of net weighs .12 pounds. What is the weight of empty box

14 Answers   Photon, Photon Infotech,


A circular road runs round a circular ground. If the difference between the circumference of the outer circle and inner circle is 44 meters, find the width of the road?

7 Answers   Tech Mahindra,


Two big cubes divided into 125 small cubes each. they placed horizontally. If column no. 1 , 3, 5, 6, 8, 10 is removed from the cubes then remaining cubes columns is painted by blue color then, 1) how many cube 0 side painted? 2) how many cube 1 side painted? 3) how many cube 2 side painted? Explain how to do ?

4 Answers   CTS,


The difference between the compound and simple interest on a certain sum for 2 years at the rate of 8% per annum is Rs.80,What is the sum?

0 Answers   Wipro,


Categories