Aptitude - Chain Rule - Discussion
Discussion Forum : Chain Rule - General Questions (Q.No. 9)
9.
A wheel that has 6 cogs is meshed with a larger wheel of 14 cogs. When the smaller wheel has made 21 revolutions, then the number of revolutions mad by the larger wheel is:
Answer: Option
Explanation:
Let the required number of revolutions made by larger wheel be x.
Then, More cogs, Less revolutions (Indirect Proportion)
14 : 6 :: 21 : x 
14 x x = 6 x 21
 x = |
6 x 21 |
| 14 |
x = 9.
Discussion:
13 comments Page 1 of 2.
Prakash said:
1 decade ago
Please explain another method for this problem.
Avaneet said:
1 decade ago
What is cogs?
Rahul said:
1 decade ago
Cogs = Tooth on the rim of gear wheel...
If cogs increases , wheel circumference increases then revolution decreases dats means
6 cogs,less circumference,more revolution..
14 cogs, more circumference ,less revolution compared to 6 cogs wheel
cogs is inversely proportional to revolutions
6 cogs gives 21 revolution
1 cog will give =6*21 revolutions.
14 cog will give = 6*21/14=9
If cogs increases , wheel circumference increases then revolution decreases dats means
6 cogs,less circumference,more revolution..
14 cogs, more circumference ,less revolution compared to 6 cogs wheel
cogs is inversely proportional to revolutions
6 cogs gives 21 revolution
1 cog will give =6*21 revolutions.
14 cog will give = 6*21/14=9
Pankaj kanaujiya said:
1 decade ago
Lets firstly we take small cog.....
6 cog = 21 revolution
1 cog = 21*6 = 126 revolution
now we have to find the revolution of 14 cog
then
14 cog = 126/14 =63/7 = 9
hence answer is B.
have a good day!!!
6 cog = 21 revolution
1 cog = 21*6 = 126 revolution
now we have to find the revolution of 14 cog
then
14 cog = 126/14 =63/7 = 9
hence answer is B.
have a good day!!!
(2)
Prasanna said:
10 years ago
Hi guys,
If you think in another way it would be easy.
Larger wheel has 14 cogs.
Smaller has 6 cogs.
So for one revolution of smaller wheel bigger will rotate 6/14.
1 revolution-----6/14.
21 revolution----21*6/14.
And is 9.
If you think in another way it would be easy.
Larger wheel has 14 cogs.
Smaller has 6 cogs.
So for one revolution of smaller wheel bigger will rotate 6/14.
1 revolution-----6/14.
21 revolution----21*6/14.
And is 9.
(1)
Anonymous said:
9 years ago
@Rahul.
How is cogs inversely proportional to revolutions?
How is cogs inversely proportional to revolutions?
SOUNDARYA said:
9 years ago
@Anonymous.
Because the given cogs are 6 which is less than that of the revolutions 2, which is more.
Because the given cogs are 6 which is less than that of the revolutions 2, which is more.
Karthik said:
8 years ago
21 is of small cog then why is it compared with lager ration?
Sandeep said:
8 years ago
You can say 6 persons can do a piece of work in 21 days than in how many days 14 person can do the same work.
6*21 =14*x.
=9.
6*21 =14*x.
=9.
(3)
Sandeep said:
8 years ago
You can say 6 persons can do a piece of work in 21 days then in how many days 14 person can do the same work.
6*21 =14*x.
=9.
6*21 =14*x.
=9.
(7)
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