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.
Lavanya said:
7 years ago
The total work done for three days means. There should be 1/10+1/10+1/10 should come right. Why they used it for 2 days only?
Rashmi maurya said:
6 years ago
a b c
20 30 60 (LCM=120)
6 4 2 (a20/120=6, b30/720=4, c60/120=2).
6 + 4 + 2 = 12,
12/120 = 5
5 * 3 = 15.
20 30 60 (LCM=120)
6 4 2 (a20/120=6, b30/720=4, c60/120=2).
6 + 4 + 2 = 12,
12/120 = 5
5 * 3 = 15.
Rajaguru said:
1 decade ago
@Manoj mass reply nice bro,
3 days = 1/5.
6 days = 2/5.
9 days = 3/5.
12 days = 4/5.
15 days = 5/5(1) == work completed.
3 days = 1/5.
6 days = 2/5.
9 days = 3/5.
12 days = 4/5.
15 days = 5/5(1) == work completed.
Animesh said:
1 decade ago
A 20--------------------3.
B 30 ---LCM 60 -------2.
C 60--------------------1.
Total = 3+2+1 = 6.
So answer = 60/6 = 10.
B 30 ---LCM 60 -------2.
C 60--------------------1.
Total = 3+2+1 = 6.
So answer = 60/6 = 10.
Trisha said:
1 decade ago
Whole work will be done in (3 x 5) = 15 days.
I m unable to understand a last step. Explain me?
How they multiply by 5?
I m unable to understand a last step. Explain me?
How they multiply by 5?
Akash kumar said:
8 years ago
Here 3'day's work is 1/5 so next 3 day work is also 1/5.
1/5+ 1/5+ 1/5+ 1/5+ 1/5 i.e its happen 5 times so 3x5= 15 days.
1/5+ 1/5+ 1/5+ 1/5+ 1/5 i.e its happen 5 times so 3x5= 15 days.
Harshal sonwane said:
3 years ago
1/5 work is done in 3 days.
The total work 1 done in x days.
Simply cross multiply;
x*1/5 = 3 * 1.
x/5 = 3,
x = 15.
The total work 1 done in x days.
Simply cross multiply;
x*1/5 = 3 * 1.
x/5 = 3,
x = 15.
(103)
Preethi said:
1 decade ago
1/5 of work being done in 3 days. But how do we arrive at the total no. Of days worked by A? what is the logic behind?
Aariz said:
9 years ago
Hey, guys. I have some confusion in this question. Is there anyone from Delhi, please guide me to solve this question.
Anu said:
7 years ago
I really didn't get the last step where they said whole work will be done in 15 days. Can anyone explain how it comes?
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