Aptitude - Time and Work - Discussion
Discussion Forum : Time and Work - General Questions (Q.No. 21)
21.
A takes twice as much time as B or thrice as much time as C to finish a piece of work. Working together, they can finish the work in 2 days. B can do the work alone in:
Answer: Option
Explanation:
| Suppose A, B and C take x, | x | and | x | days respectively to finish the work. |
| 2 | 3 |
| Then, |  |
1 | + | 2 | + | 3 |  |
= | 1 |
| x | x | x | 2 |
 |
6 | = | 1 |
| x | 2 |
x = 12.
So, B takes (12/2) = 6 days to finish the work.
Discussion:
68 comments Page 4 of 7.
Subhasish baul said:
5 years ago
A - 12.
B - 6.
C - 4.
Work as satisfied to take together 2day finished.
Efficiency A 1 B 2 C 3.
Total work 12.
Total efficiency 6.
Finished together 12 ÷ 6 = 2day satisfied
**B alone do in 12 ÷ 2 = 6 days.
B - 6.
C - 4.
Work as satisfied to take together 2day finished.
Efficiency A 1 B 2 C 3.
Total work 12.
Total efficiency 6.
Finished together 12 ÷ 6 = 2day satisfied
**B alone do in 12 ÷ 2 = 6 days.
Md Ali Umar said:
1 decade ago
Hi Mini you are making equ. 2A=B & 3A=C, but so many people a making equ. A=2B & A=3C .
Which one s correct, but both one is getting same answer. I'm confussing in this prob. Pls any one describe it ?
Which one s correct, but both one is getting same answer. I'm confussing in this prob. Pls any one describe it ?
Divya said:
1 decade ago
A=2B=3C
A+B+C=2 ----(EQ.1)
WRITING a and c in terms of b,
A=2B, C=2B/3
IN EQ.1,
2B+B+2B/3=2
3B+2B/3=2
(9B+2B)/3=2
9B+2B=2*3
11B=6
B=6/11
that means, out of 11 days, b alone completes 6 days of work.
A+B+C=2 ----(EQ.1)
WRITING a and c in terms of b,
A=2B, C=2B/3
IN EQ.1,
2B+B+2B/3=2
3B+2B/3=2
(9B+2B)/3=2
9B+2B=2*3
11B=6
B=6/11
that means, out of 11 days, b alone completes 6 days of work.
Makvana Disha said:
9 years ago
We are also doing this,
A's 1 day work = 1/x, B's 1 day work = 2/x, C's 1 day work = 3/x.
So, (A + B + C) 's one-day work:
= (1/x + 2/x + 3/x).
= (1/x + 5x/x ^ 2).
= 1/x + 5.
= 6x/x = 6 Each of three.
A's 1 day work = 1/x, B's 1 day work = 2/x, C's 1 day work = 3/x.
So, (A + B + C) 's one-day work:
= (1/x + 2/x + 3/x).
= (1/x + 5x/x ^ 2).
= 1/x + 5.
= 6x/x = 6 Each of three.
Jayasree said:
1 decade ago
@nayana
Let time taken by B be x
then b= x
a = 2x which is equal to 3c
i.e 2x = 3c
c = 2x/3
so a = 2x ; b = x ; c = 2x/3
Dividing each by 2 => x , x/2 , x/3.
Hope it is clear.
Let time taken by B be x
then b= x
a = 2x which is equal to 3c
i.e 2x = 3c
c = 2x/3
so a = 2x ; b = x ; c = 2x/3
Dividing each by 2 => x , x/2 , x/3.
Hope it is clear.
Karthick M said:
3 years ago
To simple method is:
A = 2B or A=3B
(A+B)'s 1day work = 1/2=(2B+B)'s 1day work
1/2 = 3B's 1-day work
ie, B's 1 day work = 1/6
So, B's whole work done is in 6 days.
A = 2B or A=3B
(A+B)'s 1day work = 1/2=(2B+B)'s 1day work
1/2 = 3B's 1-day work
ie, B's 1 day work = 1/6
So, B's whole work done is in 6 days.
(7)
Meera said:
1 decade ago
A+B+C's 1 days work is = 1/6.
Therefore 2'days work (A+B+C) is=1/6*2=3.
B can do the work alone (2*3) =6.
So B takes 6 days to finish the work.
Is it right method? please anyone tell me.
Therefore 2'days work (A+B+C) is=1/6*2=3.
B can do the work alone (2*3) =6.
So B takes 6 days to finish the work.
Is it right method? please anyone tell me.
Thameem said:
1 decade ago
here is another way of solving
given
a=2b
a=3c
a+b=1/2 (work from days)
use a's value in the equation
2b+b=1/2
then 3b=1/2
b=1/6
then b can done work alone in 6 days(days from work)
given
a=2b
a=3c
a+b=1/2 (work from days)
use a's value in the equation
2b+b=1/2
then 3b=1/2
b=1/6
then b can done work alone in 6 days(days from work)
Nayana said:
1 decade ago
Hi,
Can any one exaplain why they have taken x,x/2,x/3, because in the question they have given A takes twice as much as B that means two times more than B but they are dividing it.
Can any one exaplain why they have taken x,x/2,x/3, because in the question they have given A takes twice as much as B that means two times more than B but they are dividing it.
Manish said:
8 years ago
One day work of a,b&c=1/2
let a's one-day work=x , then b's one day work 2x & c work 3x
x+2x+3x=1/2
6x=1/2
x=1/12
b's one day work=2*1/12
=1/6
Therefore total work in 6 days.
let a's one-day work=x , then b's one day work 2x & c work 3x
x+2x+3x=1/2
6x=1/2
x=1/12
b's one day work=2*1/12
=1/6
Therefore total work in 6 days.
(1)
Post your comments here:
Quick links
Quantitative Aptitude
Verbal (English)
Reasoning
Programming
Interview
Placement Papers