Aptitude - Chain Rule - Discussion

Discussion :: Chain Rule - General Questions (Q.No.10)

10. 

If 7 spiders make 7 webs in 7 days, then 1 spider will make 1 web in how many days?

[A]. 1
[B].
7
2
[C]. 7
[D]. 49

Answer: Option C

Explanation:

Let the required number days be x.

Less spiders, More days (Indirect Proportion)

Less webs, Less days (Direct Proportion)

Spiders 1 : 7 :: 7 : x
Webs 7 : 1

1 x 7 x x = 7 x 1 x 7

x = 7.


Pawan Goyal said: (Oct 27, 2010)  
hw that problem has been solved i don't understand the way it has been solve out...plz tell me the way it has been solved out

Chanti said: (Jan 4, 2011)  
I didn't understood how the ratio will be considered. As follows
1*7*x=7*1*7

So please give the brief description.

Mehar said: (Feb 2, 2011)  
When ever you found these kind of problems, come from the back.

Means if 7spiders 7weds in 7days so,

1 spider work ==(7*7)/7=7;

one person work==days*work done/ number of workers;

Anjani said: (Sep 11, 2011)  
I didn't understand the solution please explain once.

Radhika said: (Sep 17, 2011)  
7 spiders in 7 days make 7 webs

Since 7 webs in 7 days.....1 web in 1 day..dis 1 web is made by 7 spiders.

Now,
Since 7 spiders have made 1web in a day
divide this 1 web into 7 parts 1 each for every spider..

So 1 spider will make 1/7 part of the web in a day.

Now,

1/7 th part completes in 1 day
so 1/7(1st day) + 1/7(2nd day) + 1/7(3rd day) + 1/7(4th day) + 1/7(5th day) + 1/7(6th day) + 1/7(7th day) = 7/7 = 1 complete web by a spider...

Thus it took 7 days which is the answer.

Prabhu said: (Sep 27, 2011)  
@RADHIKA

What an explanation great thank you.

Sudheer said: (Oct 5, 2011)  
Superb radhika. Thank you.

Deepak Verma said: (Jul 20, 2014)  
Its simple formula:-

(no. of spider*no.of days)/no.of webs

So according this:

7*7/7 = 1*x/1.
Than x = 7.

Kasinath @Hyd said: (Sep 4, 2014)  
7 Spiders ... 7 Days.

=> 1 spider =7*7= 49 days--- Eq(1).

Remaining one is 7 Webs--- Eq(2).

But, question is about 1 web. So, when we Divide Eqn(1) by Eqn(2) we get 1 web.

=>1 spider =49 days/7 webs = 7 days/1web

=>1 spider 1 web = 7 days

Kilevu said: (Aug 27, 2016)  
Nice explanations, I get it now. Thanks to all.

Anomy said: (Oct 26, 2016)  
To get 7 then I think it needs to be explained better that each spider is working on their own web.

Otherwise, it takes 1 team of 7 spiders 7 days to make 7 webs. If you have less on your team you will make fewer webs or it will take longer to make the same number of webs.

Anoms said: (Dec 23, 2016)  
3 chickens can make 3 eggs in 3 days, then how many eggs can be made by 300 chickens in 300 days?

Anonymous said: (Feb 2, 2017)  
7spiders * 1spider * x days = 7webs * 1web * 7days.
Spiders on the Left * days = webs on the right * days.
=> 7 * 1 * x = 7 * 1 * 7.
7x = 49,
7x/7 = 49/7,
x = 7days.

Mr. Mp said: (Aug 31, 2017)  
Take this example.

7 girls make 7 cakes in 7 days.
so 7 girls complete 1 cake in 1 day.
7 girls complete 2cakes in 2days.
7 girls complete 3 cakes in 3 days.
Similarly, 7 girls make 7 cakes in 7 days.

Simply can say effort of 7 girls is needed for 1 cake to complete in 1 day as good as saying effort of 1 girl is required for 7 days to make 1 cake.

Siddu K said: (Sep 14, 2017)  
@Radhika.

Super explanation.

Mayur said: (Dec 23, 2017)  
Good explanation @Radhika.

Bala said: (Apr 19, 2018)  
Nice explanation @Radhika.

Vinnu said: (Aug 30, 2018)  
Nice. Thanks all.

Mayur said: (Jan 18, 2019)  
7 Spiders make 7 Webs in 7 Days. -> eq 1
7 Spiders make 1 Web in 1Day -> eq 2
1 Spider make 1 Web in X=? Days) -> eq3

Multiple Value of Number of Spiders with a number of days from eq 2 and eq3

7*1. = 1*X.
X. =. 7*1/1,
X. = 7 -----> Ans.

Less Spiders -> More Days (Indirect Proportion).
Less Webs -> fewer Days (Direct Proportion).

Sushi said: (Mar 10, 2019)  
@Radhika.

Superb explanation, Thank you.

Pennanson said: (Apr 7, 2019)  
The correct Answer is 1.

Anonymous said: (Aug 30, 2020)  
@Radhika.

You explained it very well. Thanks.

Post your comments here:

Name *:

Email   : (optional)

» Your comments will be displayed only after manual approval.