Aptitude - Time and Work - Discussion
Discussion Forum : Time and Work - General Questions (Q.No. 7)
7.
A can do a piece of work in 4 hours; B and C together can do it in 3 hours, while A and C together can do it in 2 hours. How long will B alone take to do it?
Answer: Option
Explanation:
| A's 1 hour's work = | 1 | ; |
| 4 |
| (B + C)'s 1 hour's work = | 1 | ; |
| 3 |
| (A + C)'s 1 hour's work = | 1 | . |
| 2 |
| (A + B + C)'s 1 hour's work = |  |
1 | + | 1 |  |
= | 7 | . |
| 4 | 3 | 12 |
| B's 1 hour's work = | |
7 | - | 1 | |
= | 1 | . |
| 12 | 2 | 12 |
B alone will take 12 hours to do the work.
Discussion:
97 comments Page 7 of 10.
SUREKHA said:
1 year ago
A = 1/4
B + C = 1/3
A+C = 1/2
B =?
A + (B + C) - (A + C) = 1/4 + 1/3 - 1/2
B = 1/12.
B = 12 DAYS.
B + C = 1/3
A+C = 1/2
B =?
A + (B + C) - (A + C) = 1/4 + 1/3 - 1/2
B = 1/12.
B = 12 DAYS.
(16)
Sonu said:
1 decade ago
A=1/4
B+C=1/3
A+C=1/2
----------(subtracting on both sides)
B-A=(-)1/6
B=(- 1/6)+(1/4)
B=1/12
Therefore, 12 hours!!!!
B+C=1/3
A+C=1/2
----------(subtracting on both sides)
B-A=(-)1/6
B=(- 1/6)+(1/4)
B=1/12
Therefore, 12 hours!!!!
Pavan@9966606261 said:
1 decade ago
Hi friends
b+c=1/3;
a+c=1/2;
a=1/4;
c=1/2-1/4=1/4;
b=1/3-1/4=1/12;
time taken for B alone to complete is 12 hours
b+c=1/3;
a+c=1/2;
a=1/4;
c=1/2-1/4=1/4;
b=1/3-1/4=1/12;
time taken for B alone to complete is 12 hours
Rajin said:
1 decade ago
A = 1/4
B+C = 1/3
A+C = 1/2
A+B+C = 1/4+ 1/3 = 7/12
TO FIND B'W WORK
A+B+C - (A+C) = 7/12 - 1/2 = 1/12
B+C = 1/3
A+C = 1/2
A+B+C = 1/4+ 1/3 = 7/12
TO FIND B'W WORK
A+B+C - (A+C) = 7/12 - 1/2 = 1/12
Anil said:
9 years ago
By solving this three equation, we will get the answer.
1/A = 1/4.
1/B + 1/C = 1/3.
1/A + 1/C = 1/2.
1/A = 1/4.
1/B + 1/C = 1/3.
1/A + 1/C = 1/2.
Bunny said:
8 years ago
Thank you so much @Himanshi Mishra.
I was looking for this LCM method. This is way too easy. Thanks.
I was looking for this LCM method. This is way too easy. Thanks.
HARRY said:
1 decade ago
C=1/2-1/4=>1/4(C'S 1 DAY WORK)
B=1/3-1/4=>1/12(B'S 1 DAY WORK)
SO 12 DAYS TO COMPLETE THE WORK
B=1/3-1/4=>1/12(B'S 1 DAY WORK)
SO 12 DAYS TO COMPLETE THE WORK
ESNALA SIDDA said:
2 months ago
A = 1/4.
B + C = 1/3.
A + C = 1/2.
C = 1/2-1/4.
= 1/4,
B = 1/3 - 1/4.
= 1/12.
=12hrs.
B + C = 1/3.
A + C = 1/2.
C = 1/2-1/4.
= 1/4,
B = 1/3 - 1/4.
= 1/12.
=12hrs.
(2)
Lazy Balu said:
6 years ago
A+(B+C)-(C+A) = 1/4+1/3-1/2.
A+B+C-C-A = (3+4-6)/12.
Therefore B = 1/12.
So B can do in 12 days.
A+B+C-C-A = (3+4-6)/12.
Therefore B = 1/12.
So B can do in 12 days.
Arun said:
1 decade ago
Just simply i know that A's is 1/4
B+C is 1/3
So do it
1/3 - 1/4
And u get 1/12
B's work 12 hour
B+C is 1/3
So do it
1/3 - 1/4
And u get 1/12
B's work 12 hour
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