Aptitude - Chain Rule - Discussion
Discussion Forum : Chain Rule - General Questions (Q.No. 5)
5.
39 persons can repair a road in 12 days, working 5 hours a day. In how many days will 30 persons, working 6 hours a day, complete the work?
Answer: Option
Explanation:
Let the required number of days be x.
Less persons, More days (Indirect Proportion)
More working hours per day, Less days (Indirect Proportion)
| Persons | 30 | : | 39 |  |
:: 12 : x |
| Working hours/day | 6 | : | 5 |
30 x 6 x x = 39 x 5 x 12
 x = |
(39 x 5 x 12) |
| (30 x 6) |
x = 13.
Discussion:
32 comments Page 2 of 4.
Pavan Power star fan said:
9 years ago
Here 39 men work for 5 * 12 hrs totally to complete the road.
Let x be the no of days that 30 people work, then the no of hours 30 people take to complete road is 6x hours.
The amount of work done is inversely proportional to no. of working hours.
i.e
(39/30) = (6x/60).
x = 13.
Hope you understand.
Let x be the no of days that 30 people work, then the no of hours 30 people take to complete road is 6x hours.
The amount of work done is inversely proportional to no. of working hours.
i.e
(39/30) = (6x/60).
x = 13.
Hope you understand.
Nilesh Tripathi said:
9 years ago
@Pratswinz.
You explained it in the best way. Thanks, it's very helpful.
You explained it in the best way. Thanks, it's very helpful.
Santosh k said:
9 years ago
For the first statement Total man hours = 39*12*5.
Again for the second statement man hours = 30*X*6.
Equating both equation X = 39*12*5/30*X*6 = 13 days.
Again for the second statement man hours = 30*X*6.
Equating both equation X = 39*12*5/30*X*6 = 13 days.
Appu said:
9 years ago
39*12*5 = 2340.
30*x*6 = 2340.
x = 2340/180 = 13.
30*x*6 = 2340.
x = 2340/180 = 13.
(1)
SUKUMAR SATYEN said:
1 decade ago
39 persons ---> 5 hrs per day ---> 1 work ---> 12 days.
1 person ---> 5 hrs per day ---> 1 work ---> 12 x 39 days.
1 person ---> 1 hr per day ---> 1 work ---> 12 x 39 x 5 days.
30 persons ---> 1 hr per day ---> 1 work ---> 12 x 39 x 5/30 days.
30 persons ---> 6 hrs per day ---> 1 work ---> 12 x 39 x 5/(30 x 6) days.
30 persons ---> 6 hrs per day ---> 1 work ---> 13 days.
1 person ---> 5 hrs per day ---> 1 work ---> 12 x 39 days.
1 person ---> 1 hr per day ---> 1 work ---> 12 x 39 x 5 days.
30 persons ---> 1 hr per day ---> 1 work ---> 12 x 39 x 5/30 days.
30 persons ---> 6 hrs per day ---> 1 work ---> 12 x 39 x 5/(30 x 6) days.
30 persons ---> 6 hrs per day ---> 1 work ---> 13 days.
(1)
Buddhika said:
1 decade ago
M1D1H1 = M2D2H2
39*12*5 = 30*D*6.
2340 = 180d.
13 = d.
39*12*5 = 30*D*6.
2340 = 180d.
13 = d.
Lipu said:
1 decade ago
39 persons can repair in 60 hours.
1 person can do in 60*39 hours.
30 persons can do it in(60*39)/30 hours = 78 hours.
If they work 6 hours a day.
So no.of days is 78/6 = 13 days.
1 person can do in 60*39 hours.
30 persons can do it in(60*39)/30 hours = 78 hours.
If they work 6 hours a day.
So no.of days is 78/6 = 13 days.
Nisha said:
1 decade ago
The sum of infinity of a geometric series is 60. If its first term is 80, find the common ratio? can you give the answers?
Raja said:
1 decade ago
The total number of hours of work is 39(people)*60 (Working 60 hours) = 2340.
Now 30 people working 6 hours so the number of days are 2340/180 = 13.
Now 30 people working 6 hours so the number of days are 2340/180 = 13.
Mithilesh said:
1 decade ago
1 person can do this work in 39*12*5 = 2340 hrs.
Hence 30 persons will do in 2340/30 = 78 hrs = 78/6 13 days.
I think its very understandable.
Hence 30 persons will do in 2340/30 = 78 hrs = 78/6 13 days.
I think its very understandable.
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