Ratios & Proportion
Aptitude

 Back to Questions
Q.

Two cogged wheels of which one has 32 cogs and other 54 cogs, work into each other. If the latter turns 80 times in three quarters of a minute, how often does the other turn in 8 seconds?

 A.

48

 B.

24

 C.

38

 D.

None of these

 Hide Ans

Solution:
Option(B) is correct

Less Cogs ⇒ more turns and less time ⇒ less turns

Table below can be scrolled horizontally

  Cogs Time Turns
A 54 45 80
B 32 8 ?

Number of turns required= \(80\times \dfrac{54}{32}\times \dfrac{8}{45}=24\text{ times}\)


(3) Comment(s)


Bushra
 ()

More explanation req pls..


Deepak
 ()

I've added a table to the solution, this might be helpful to you.


Suhail
 ()

We are equating the rate at which it rotates per second,
So we get 80 times per 45 second times number of cogs = x times per 8 seconds times the number of cogs.
54*(80/45)=32*(x/8)

Hope you have got it!