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 11 of 36.
JPV said:
8 years ago
Hi, I'm not getting the below logic in quotes
" Complete 3 days work is 1/10 + 1/10 = 2/10 =1/5"
Shouldn't that be [ (A's ist day)+ (A's 2nd day) + (A+B+C combined on 3rd day)]?
ie = 1/20 + 1/10 + 1/10?
Please correct me if I am wrong.
" Complete 3 days work is 1/10 + 1/10 = 2/10 =1/5"
Shouldn't that be [ (A's ist day)+ (A's 2nd day) + (A+B+C combined on 3rd day)]?
ie = 1/20 + 1/10 + 1/10?
Please correct me if I am wrong.
Benny said:
1 decade ago
Here my simple ans:
A is working continue 2 day's.So he's 2day's work is:1/20*2=1/10;
in 3rd day he join other two person B and C.So here 3 member work:
1/20+1/30+1/60=1/10;
3 day's work is :1/0+1/10=1/5
So total work done by them is 10+5=15;
A is working continue 2 day's.So he's 2day's work is:1/20*2=1/10;
in 3rd day he join other two person B and C.So here 3 member work:
1/20+1/30+1/60=1/10;
3 day's work is :1/0+1/10=1/5
So total work done by them is 10+5=15;
(1)
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)
Md Toufique said:
7 years ago
Let us suppose total work to be done is 60 unit, then A, B and C's one day work is 3, 2, 1 respectively,
Then in every 3 days they will finish 12 unit of work (3, 3, 6),
Then, 12 + 12 + 12 + 12+ 12 =60 work done so total days = 3+3+3+3+3=15.
Then in every 3 days they will finish 12 unit of work (3, 3, 6),
Then, 12 + 12 + 12 + 12+ 12 =60 work done so total days = 3+3+3+3+3=15.
Divya said:
8 years ago
Simply;
A's 3 days works ----- 3/20.
B and C join on 3rd day so;
(A+B+C)'s 3 days work will be ---- 3/20 +1/30+ 1/60 = 12/60 = 1/5.
3 days work -- 1/5 then;
1 day work -- 1/15 part of 1 work (i.e 1/15 work in 1 days),
15 days = 1 work.
A's 3 days works ----- 3/20.
B and C join on 3rd day so;
(A+B+C)'s 3 days work will be ---- 3/20 +1/30+ 1/60 = 12/60 = 1/5.
3 days work -- 1/5 then;
1 day work -- 1/15 part of 1 work (i.e 1/15 work in 1 days),
15 days = 1 work.
Susi said:
1 decade ago
A's 2 days work: (1/20*2).
Answer: 1/10.
A, B, C add 1 days work. (1/20 add 1/30 add 1/60).
Answer: (110/36000).(110/2/36000/600).
Answer: (5 add 1/60).
Answer: 1(1/10).
Three days work (1/10 Add 1/10).
Answer (1/5)*3.
Answer: 16.
Answer: 1/10.
A, B, C add 1 days work. (1/20 add 1/30 add 1/60).
Answer: (110/36000).(110/2/36000/600).
Answer: (5 add 1/60).
Answer: 1(1/10).
Three days work (1/10 Add 1/10).
Answer (1/5)*3.
Answer: 16.
Sai Kumar Reddy Nossam said:
7 years ago
Common multiple of A,B & C is 120.
A's one day work =120/20 = 6 units,
B's one day work =120/30 = 4 units,
C' one day work = 120/60 = 2 units,
work done in three days by A, B, C= 24 units.
So, the total work = (120/24) * 3 = 15 days.
A's one day work =120/20 = 6 units,
B's one day work =120/30 = 4 units,
C' one day work = 120/60 = 2 units,
work done in three days by A, B, C= 24 units.
So, the total work = (120/24) * 3 = 15 days.
Seema duhan said:
1 decade ago
First Two days work done by A = (1/20)+(1/20)=> 2/20=> 1/10.
Third day work done by A, B, C = (1/20)+(1/30)+(1/60)=> 6/60 => 1/10.
3 days work done: 1/5.
Then 1 day work done: (1/5)*(1/3) = 1/15.
So the answer is 115 days.
Third day work done by A, B, C = (1/20)+(1/30)+(1/60)=> 6/60 => 1/10.
3 days work done: 1/5.
Then 1 day work done: (1/5)*(1/3) = 1/15.
So the answer is 115 days.
Vijay said:
1 decade ago
B and C joined with A for every 3 days.
So their (A,B,C) 3 days work is == (A's 2 days work i.e. [1/10]) + (A+B+C 's 1 day work i.e [1/10]).
= 1/10+1/10 = 1/5.
So for 3 days 1/5 work is done.
So total work will complete in 15 days.
So their (A,B,C) 3 days work is == (A's 2 days work i.e. [1/10]) + (A+B+C 's 1 day work i.e [1/10]).
= 1/10+1/10 = 1/5.
So for 3 days 1/5 work is done.
So total work will complete in 15 days.
Pavethra said:
1 decade ago
I tell that third day alone A join them so on third day it is 1/20 +1/30+1/60=1/10(here a,b,c all work together)
then 2 days A never join them then B and C work together
then SO 1/20 +1/30=1/5
then make it ulta 10+5=15days
easy na.
then 2 days A never join them then B and C work together
then SO 1/20 +1/30=1/5
then make it ulta 10+5=15days
easy na.
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