Interested to Buy Any Domain ? << Click Here >> for more details...
Assume that you have just heard of a scandal and you are the
first one to know. You pass it on to
four person in a matter of 30 minutes. Each of these four in
turn passes it to four other persons
in the next 30 minutes and so on.
How long it will take for everybody in the World to get to
know the scandal?
- 3 Answers
- 16295 Views
- I also Faced
- E-Mail Answers
Answers were Sorted based on User's Feedback
Answer / guest
Assume that nobody hears it more than once and the
population of the World is approximately 5.6
billions.
Everybody in the World will get to know the scandal in 8 hours.
You came to know of a scandal and you passed it on to 4
persons in 30 minutes. So total (1+4) 5
persons would know about it in 30 minutes.
By the end of one hour, 16 more persons would know about it.
So total of (1+4+16) 21 persons would
know about it in one hour.
Similarly, the other (1+4+16+64) persons would have know
about it in one and a half hours.
(1+4+16+64+256) persons would have know about it in two
hours and so on...
It can be deduced that the terms of the above series are the
power of 4 i.e. 4^0, 4^1, 4^2, 4^3 and
so on upto (2N+1) terms. Also, the last term would be 4^2N
where N is the number of hours.
Sum of the above mentioned series = [4^(2N+1)-1]/3
The sum of the series must be 5.6 billions. Hence, equating
the sum of the series with 5.6
billions, we get N=8 hours.
Scandals travel FAST !!!
| Is This Answer Correct ? | 17 Yes | 2 No |
Answer / arvind ragunathan
the sum goes out this way : 4+4^2+.....4^11 to reach 5.6
billion. the 30 minutes count starts with 5 people. so
there are 10 '30 minutes' in this sum. that amounts to 300
minutes. hence 5 hours.
| Is This Answer Correct ? | 0 Yes | 1 No |
Answer / swati
I dont know the answer, but wud like to do one small
correction in first answer posted..
in first 30 mins 4 people will come to know..
after that, for next 30 mins total 1+4 = 5 people including
urself are ready to inform another 20 people..
it's not da condition that, once u told to 4 people, u cant
continue with telling to 4 new poeople about it..
right..?! ;)
now, at da end of 1 hour total 25 people know about
scandal..
and so on........ :)
| Is This Answer Correct ? | 1 Yes | 4 No |
1. at the recent web developers bowling match, two games weree played. kiev beat stuart in both games; also richard beat john in both games. The winner in game 1 came second in game 2. richard won game 2 and john beat stuart in game1. no player got the saame placing twice. can you determine who finished where in each game?
There are 2 items combined cost is 110.. one item cost is 100 rupees more than the cost of other. So tell me indiviual cost of items......
All types of puzzles asked in SBI exam.
0 Answers State Bank Of India SBI,
A,B,C,D are four teams.Three guys x,y,z comment about matches between four teams , X said either A or B will win Y says A will never win Z says C or B will not win only one of them is correct then who won the match.
If a rook and a bishop of a standard chess set are randomly placed on a chessboard, what is the probability that one is attacking the other? Note that both are different colored pieces.
Difference between Bholu's and Molu's age is 2 years and the difference between Molu's and Kolu's age is 5 years. What is the maximum possible value of the sum of the difference in their ages, taken two at a time?
Hi, this is das. i will attend bank of baroda 2008 clerical exam. i need model bank exam question papers. please send me. this is my mail id: thulasi.dasan@yahoo.co.in
3 blocks are chosen randomly on a chessboard. What is the probability that they are in the same diagonal?
Taurus+pisces =scorpio,substitute the digits for the following letter to make the following addition true?
There are 8 stones which are similar except one which is heavier than the others. To find it, you are given a pan balance. What is the minimal number of weighing needed to find out the heaviest stone ?
there is a desert. a professor has to cross it n it takes 6days for him to cross. there are enough food reserves and students who can help d professor cross d desert. each person including professor can carry only 4 food packets with him while crossing the desert. in d desert also, each person can hav at the most 4 packets with him and they need to eat one packet per person per day during their travel. how wil d professor reach the other side of desert??
Substitute digits for the letters to make the following subtraction problem true. S A N T A - C L A U S ----------------- X M A S Note that the leftmost letter can't be zero in any word. Also, there must be a one-to-one mapping between digits and letters. e.g. if you substitute 3 for the letter M, no other letter can be 3 and all other M in the puzzle must be 3.
English 
