Question

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 ? select one: 50 min 47.5 min 49 min 500 min

Answer 1

Answer:

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....

Step-by-step explanation:

Answer 2

Concept:

Time is the ongoing progression of existence and things that happen in what seems to be an irrevocable order from the past, present, and forward into the future. Time may be described in mathematics as a continuing and continuous series of events that take place one after another, from the past through the present and into the future. The length of events or the gaps between them may be measured, compared, or even ordered using time.

Given:

Here it is given that a secret can be told only $2$ persons in $5$ minutes .the same person tells to $2$ more persons and so on.

Find:

We have to find how long will take to tell it to $768$ persons.

Solution:

According to the question, a secret can be told only $2$ persons in $5$ minutes .the same person tells to $2$ more persons and so on.

Now, $2^9=512$

And $2^{10}=1024$  but, total no. of persons$=768$.

that is $512+256(or 2^8)$

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 $45+2.5=47.5$ $mins$.

Hence, the time required will be $47.5 mins$.

#SPJ2