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.
H.R said:
1 decade ago
@Anila.
Persons*days*hours = Persons*days*hours.
Persons*days*hours = Persons*days*hours.
Aranya said:
1 decade ago
Persons 30 : 39 :: 12 : x.
Working hours/day 6 : 5.
How did we get the following line?
30 x 6 x x = 39 x 5 x 12.
Working hours/day 6 : 5.
How did we get the following line?
30 x 6 x x = 39 x 5 x 12.
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.
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.
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?
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.
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.
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)
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)
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.
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