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 1 of 36.
Madhu said:
5 hours ago
Yes, I think 20 is the correct answer.
Suram Ramana Reddy said:
3 weeks ago
A = 20/60 -> 3 units
B = 30/60 -> 2 units
C = 60/60 -> 1 unit
= 6 units.
L.C.M=60
B and C help on every third day, which means A can do the work alone for 2 days.
2 days A work = 3x3 = 9 units + 3rd day(A+B+C) 6 = 15.
B = 30/60 -> 2 units
C = 60/60 -> 1 unit
= 6 units.
L.C.M=60
B and C help on every third day, which means A can do the work alone for 2 days.
2 days A work = 3x3 = 9 units + 3rd day(A+B+C) 6 = 15.
(12)
Krishna said:
3 months ago
Here, A alone complete the whole work then answer is 20. Because total work is 60 and A's efficiency is 3.
Then 60/3 = 20 days.
Then 60/3 = 20 days.
(4)
Deepa said:
3 months ago
LCM of A, B, C's works = 60,
And the work done by A in 1 day = 3 (60/20),
so in 2 days work done by A is = 3*2= 6,
And work done by A+B+C in 1 day = 6 [(60/20) + (60/30) + (60/60)],
So total work done for 3 days = 12,
So the total number of days required to complete 60 units of work = 60 * 3/12 = 15.
And the work done by A in 1 day = 3 (60/20),
so in 2 days work done by A is = 3*2= 6,
And work done by A+B+C in 1 day = 6 [(60/20) + (60/30) + (60/60)],
So total work done for 3 days = 12,
So the total number of days required to complete 60 units of work = 60 * 3/12 = 15.
(7)
Shreemanjesh said:
5 months ago
A = 20, B = 30, c = 60,
LCM = 60,
A = 3,
b = 2,
C = 1.
A = 3 × 3 = 9 + (abc)6 = 15.
LCM = 60,
A = 3,
b = 2,
C = 1.
A = 3 × 3 = 9 + (abc)6 = 15.
(36)
RAJA said:
5 months ago
Why have to take 3 days of work?
(18)
Abishek Aryal said:
7 months ago
In 1 day A can do 1/20.
In 3 days A can do 3/20.
In 1 day B can do 1/30.
In 1 day c can da 1/60
In 3 days ( 3 day of A+ 1 day of B + 1 day of C) = 1/5.
Now,
1/5 in 3 days.
1 in 15 days.
In 3 days A can do 3/20.
In 1 day B can do 1/30.
In 1 day c can da 1/60
In 3 days ( 3 day of A+ 1 day of B + 1 day of C) = 1/5.
Now,
1/5 in 3 days.
1 in 15 days.
(51)
Subham said:
8 months ago
A can do 20.
B can do 30.
C can do 60.
Total work (LCM of Total time)= 60
Now one day work
A's One day work 3.
B's One day work 2.
C's One day work 1.
Now A 2 days work 3 × 2 = 6.
Now B and c join after 3 days (2+1)×3 = 9
Now 6 + 9 = 15 (Ans).
B can do 30.
C can do 60.
Total work (LCM of Total time)= 60
Now one day work
A's One day work 3.
B's One day work 2.
C's One day work 1.
Now A 2 days work 3 × 2 = 6.
Now B and c join after 3 days (2+1)×3 = 9
Now 6 + 9 = 15 (Ans).
(83)
Naren kumar B said:
2 years ago
A = 20,
B = 30,
C = 60.
Find 1/A + ((1/B + 1/C)/3).
= 15 => Answer.
B = 30,
C = 60.
Find 1/A + ((1/B + 1/C)/3).
= 15 => Answer.
(193)
Aya adel said:
2 years ago
a=1/20
b=1/30
c=1/60.
So a + b + c = 1/10.
Work done in 3 days =1/20 + 1/20 + 1/10 = 1/5.
The second 3 days will be 2/5,
Third 3 days 3/5,
Fourth 3 days 4/5,
Fifth 3 days 5/5,
So, A needs 3*5 = 15 days.
b=1/30
c=1/60.
So a + b + c = 1/10.
Work done in 3 days =1/20 + 1/20 + 1/10 = 1/5.
The second 3 days will be 2/5,
Third 3 days 3/5,
Fourth 3 days 4/5,
Fifth 3 days 5/5,
So, A needs 3*5 = 15 days.
(132)
Post your comments here:
Quick links
Quantitative Aptitude
Verbal (English)
Reasoning
Programming
Interview
Placement Papers