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 13 of 36.
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)
Nike said:
8 years ago
We have A work 2 days alone third-day B&C are added that means A+A+ (A+B+C) THIS is 3days work.
So A can do 2days work=1/10, and A+B+C 1day work=1/10, so add 1/10+1/10=1/5then total day work by A is 3*5=15.
So A can do 2days work=1/10, and A+B+C 1day work=1/10, so add 1/10+1/10=1/5then total day work by A is 3*5=15.
Billal Hossain said:
5 years ago
Solution:
A's 3 days work = 3/20.
(B+C)'s 3rd day or 1 day work= 1/20.
(A+B+C)'s 3 days work = (3/20+1/20).
= 1/5.
A's 1/5 part work in 3 days.
1 part ---> 15 days.
A can do the wok in 15 days (Ans).
A's 3 days work = 3/20.
(B+C)'s 3rd day or 1 day work= 1/20.
(A+B+C)'s 3 days work = (3/20+1/20).
= 1/5.
A's 1/5 part work in 3 days.
1 part ---> 15 days.
A can do the wok in 15 days (Ans).
Suresh Kumar said:
1 decade ago
@Divya.
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.
Total work Done in 3 days= (1/10)+(1/10)=2/10 =>1/5.
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.
Total work Done in 3 days= (1/10)+(1/10)=2/10 =>1/5.
Abhishek said:
10 years ago
Let A does work in x days.
Let B does work in y days.
y - x = 60.
3x = y.
3x-x = 60.
x = 30.
y = 90.
Hence, both will do work in (1/30+1/90) = 6/135.
No of days = 135/6.
22.5 = 45/2.
Answer = 22.1/2.
Let B does work in y days.
y - x = 60.
3x = y.
3x-x = 60.
x = 30.
y = 90.
Hence, both will do work in (1/30+1/90) = 6/135.
No of days = 135/6.
22.5 = 45/2.
Answer = 22.1/2.
Subash patra said:
8 years ago
Take whole work is 1.B and C assists A only 3rd day.
So A"s two day work is 1/10.
On 3rd day total work is done is 1/5.
That means 1/5 work done taken in 3rd day. So whole work(1) is done in 15 days.
So A"s two day work is 1/10.
On 3rd day total work is done is 1/5.
That means 1/5 work done taken in 3rd day. So whole work(1) is done in 15 days.
Satyendra Sharma said:
2 decades ago
3 days work = 1/5
it means 1 day work =1/15
that is 1/15 work is done in 1 Day
now 4/5 part of work that is (1-1/5) will be done in :15*4/5 =12 days....
Hence total work done will done in (12 + 3 ) days...
it means 1 day work =1/15
that is 1/15 work is done in 1 Day
now 4/5 part of work that is (1-1/5) will be done in :15*4/5 =12 days....
Hence total work done will done in (12 + 3 ) days...
(1)
Saf said:
1 decade ago
There is confusion because the number is same for A working for 2 days (i.e.1/10 Days) and all three, A+B+C=1/10 days.
Hence its.
=2 working days of A 1/10+ All 3 together 1/10 days.
i.e. (1/10+1/10).
Hence its.
=2 working days of A 1/10+ All 3 together 1/10 days.
i.e. (1/10+1/10).
Rohit said:
1 decade ago
1st day A's + 2nd day A's work = (1/20 + 1/20) = 2/20 = 1/10--(1)
3rd day work is added by B's and C's work so, work done by A+B+C=
(1/20+1/30+1/60) = 1/10--(2)
from (1) and (2)= 1/10+1/10 =1/10
3rd day work is added by B's and C's work so, work done by A+B+C=
(1/20+1/30+1/60) = 1/10--(2)
from (1) and (2)= 1/10+1/10 =1/10
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.
Post your comments here:
Quick links
Quantitative Aptitude
Verbal (English)
Reasoning
Programming
Interview
Placement Papers