Aptitude - Chain Rule - Discussion
Discussion Forum : Chain Rule - General Questions (Q.No. 14)
14.
36 men can complete a piece of work in 18 days. In how many days will 27 men complete the same work?
Answer: Option
Explanation:
Let the required number of days be x.
Less men, More days (Indirect Proportion)
27 : 36 :: 18 : x 
27 x x = 36 x 18
 x = |
36 x 18 |
| 27 |
x = 24.
Discussion:
14 comments Page 2 of 2.
Vinod Chavan said:
9 years ago
36 men - 18 days.
27 men - ?.
x = 36 x 18.
27.
Answer is x = 24.
27 men - ?.
x = 36 x 18.
27.
Answer is x = 24.
POORNI said:
8 years ago
How to find direct and indirect proportion? Please explain this.
Yash said:
8 years ago
Why we can not do cross multiplication? please explain.
Jefferson said:
6 years ago
@Yash
Cross multiplication does not apply here.
First, You have to identify whether it's direct or indirect proportion.
In this case, it's indirect because more men take less time to complete a job compared to a few men.
Therefore we let no. of days 27men take be x
Men: days
36 : 18
27 : x.
But for indirect proportion XY=constant.
36*18 =27*x.
Hence x = 36*18/27.
Thus x=24.
Cross multiplication does not apply here.
First, You have to identify whether it's direct or indirect proportion.
In this case, it's indirect because more men take less time to complete a job compared to a few men.
Therefore we let no. of days 27men take be x
Men: days
36 : 18
27 : x.
But for indirect proportion XY=constant.
36*18 =27*x.
Hence x = 36*18/27.
Thus x=24.
(1)
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