Aptitude - Time and Work - Discussion
Discussion Forum : Time and Work - General Questions (Q.No. 3)
3.
A, B and C can do a piece of work in 20, 30 and 60 days respectively. In how many days can A do the work if he is assisted by B and C on every third day?
Answer: Option
Explanation:
| A's 2 day's work = |  |
1 | x 2 |  |
= | 1 | . |
| 20 | 10 |
| (A + B + C)'s 1 day's work = | |
1 | + | 1 | + | 1 | |
= | 6 | = | 1 | . |
| 20 | 30 | 60 | 60 | 10 |
| Work done in 3 days = | |
1 | + | 1 | |
= | 1 | . |
| 10 | 10 | 5 |
| Now, | 1 | work is done in 3 days. |
| 5 |
Whole work will be done in (3 x 5) = 15 days.
Discussion:
357 comments Page 19 of 36.
Chittu said:
10 years ago
B and C can complete this work in 20 days.
B and C one day work will be = (1/20).
Instead of assuming every third day B and C will join A in work, let us reduce the efficiency of B and C by 3 so this makes B and C one day as 1/60.
So now doing the calculations.
(1/20)+(1/60) = 1/15. Hence they can complete the work in 15 days.
Please let me know in case of any clarifications needed.
B and C one day work will be = (1/20).
Instead of assuming every third day B and C will join A in work, let us reduce the efficiency of B and C by 3 so this makes B and C one day as 1/60.
So now doing the calculations.
(1/20)+(1/60) = 1/15. Hence they can complete the work in 15 days.
Please let me know in case of any clarifications needed.
Chirag gupta said:
10 years ago
I read this but understood nothing please explain in easiest way.
Shivam said:
10 years ago
Let n be the no. of total days required;
A's one day work = 1/10.
B's = 1/30, C's = 1/60.
So n(1/10)+n/3(1/30+1/60) = 1.
From here, we get n = 15.
A's one day work = 1/10.
B's = 1/30, C's = 1/60.
So n(1/10)+n/3(1/30+1/60) = 1.
From here, we get n = 15.
Siddhu said:
10 years ago
Here a work can be completed in by A in 20 days and on third day B and C assist that means A should work for 14 days and remaining 6 days work is assisted by B and C. So help me solve in this way.
Akash said:
10 years ago
Hey why in last we multiplied 1/5 with 3?
Priya said:
10 years ago
How to solve (1/20+1/30+1/60)?
Parth said:
10 years ago
What is the Mean assisted in this question?
Praveen said:
10 years ago
1/5x100-20 percent work done in 3 days therefore for 100 cross multiply 15 days.
Nitin said:
10 years ago
A = 20 = 1 day work of A = 3 LCM = 60.
B = 30 = 1 day work of B = 2.
C = 60 = 1 day work of C = 1.
Day 1 2 3 1 2 3.
Work 3 3 (A+B+C = 3+2+1).
Work of 3 days = 2(A) + (A+B+C).
2*3+(3+2+1) = 12.
3 days = 12 unit work (which number we multiply both side that do not greater than the total unit work).
3*5 days = 12*5 unit work.
15 days = 60 unit.
B = 30 = 1 day work of B = 2.
C = 60 = 1 day work of C = 1.
Day 1 2 3 1 2 3.
Work 3 3 (A+B+C = 3+2+1).
Work of 3 days = 2(A) + (A+B+C).
2*3+(3+2+1) = 12.
3 days = 12 unit work (which number we multiply both side that do not greater than the total unit work).
3*5 days = 12*5 unit work.
15 days = 60 unit.
Onkar said:
10 years ago
A can complete a work in 20 days, B can complete the same work in 30 days and with the help of C together if they complete the work in 60 days, so assume total work to be done is 60. (LCM of 20, 30, 60).
Persons A B C per 3 day.
Days- 20 30 60 12 = 6+6.
Work/day- 3 2 1 5.
----------------------------------------------------------------.
Work - 60 60 60 60.
Per 3 day ----> 12.
How many ----> 60 = (60*3)/12 = 15 days required.
Days required.
Persons A B C per 3 day.
Days- 20 30 60 12 = 6+6.
Work/day- 3 2 1 5.
----------------------------------------------------------------.
Work - 60 60 60 60.
Per 3 day ----> 12.
How many ----> 60 = (60*3)/12 = 15 days required.
Days required.
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