Aptitude - Time and Work - Discussion
Discussion Forum : Time and Work - General Questions (Q.No. 8)
8.
A can do a certain work in the same time in which B and C together can do it. If A and B together could do it in 10 days and C alone in 50 days, then B alone could do it in:
Answer: Option
Explanation:
| (A + B)'s 1 day's work = | 1 |
| 10 |
| C's 1 day's work = | 1 |
| 50 |
| (A + B + C)'s 1 day's work = |  |
1 | + | 1 |  |
= | 6 | = | 3 | . .... (i) |
| 10 | 50 | 50 | 25 |
A's 1 day's work = (B + C)'s 1 day's work .... (ii)
| From (i) and (ii), we get: 2 x (A's 1 day's work) = | 3 |
| 25 |
 A's 1 day's work = |
3 | . |
| 50 |
 B's 1 day's work |
|
1 | - | 3 | |
= | 2 | = | 1 | . |
| 10 | 50 | 50 | 25 |
So, B alone could do the work in 25 days.
Discussion:
147 comments Page 7 of 15.
Subhash said:
1 year ago
A = B + C.
Lcm of 10 and 50 = 50 ( Total Work)
Eff of A + B = 5 --->1.
Eff of C = 1.
A = 5- B from 1.
A = B + C.
5 - B = B + 1.
B = 2.
Time= TW/Eff of B.
= 50/2 = 25.
Lcm of 10 and 50 = 50 ( Total Work)
Eff of A + B = 5 --->1.
Eff of C = 1.
A = 5- B from 1.
A = B + C.
5 - B = B + 1.
B = 2.
Time= TW/Eff of B.
= 50/2 = 25.
(26)
Raghu said:
6 years ago
A=B+C --- (1).
A+B=1/10 --- (2).
C=1/50 --- (3).
Substitute C in eq 1.
A=B+ (1/50).
From eq 2 we get A= (1/10) -B.
Substitute this in above eq.
(1/10)-B=B+ (1/50).
Solve it.
A+B=1/10 --- (2).
C=1/50 --- (3).
Substitute C in eq 1.
A=B+ (1/50).
From eq 2 we get A= (1/10) -B.
Substitute this in above eq.
(1/10)-B=B+ (1/50).
Solve it.
(1)
Anonymous said:
9 years ago
A = B + C.
A + B = 1/10.
A = 1/10 - B.
C = 1/50.
A = B + C.
1/10 - B = B + 1/50.
(1- 10B) /10= (50B + 1) /50.
50 - 500B = 500B + 10.
100B = 40.
B = 40/100.
B = 1/25.
B = 25.
A + B = 1/10.
A = 1/10 - B.
C = 1/50.
A = B + C.
1/10 - B = B + 1/50.
(1- 10B) /10= (50B + 1) /50.
50 - 500B = 500B + 10.
100B = 40.
B = 40/100.
B = 1/25.
B = 25.
K Mohammad Rizwan said:
4 months ago
1/A = 1/B + 1/ C -->1
1/A + I/B = 1/10 -->2
1/C = 1/50 -->3
Subs 1 in 2.
1/B + 1/C + 1/B = 1/10 -->4
Subs 3 in 4.
2/B = 1/10 - 1/50.
2/B = 4/50,
B = 25.
1/A + I/B = 1/10 -->2
1/C = 1/50 -->3
Subs 1 in 2.
1/B + 1/C + 1/B = 1/10 -->4
Subs 3 in 4.
2/B = 1/10 - 1/50.
2/B = 4/50,
B = 25.
(4)
Bunny said:
4 years ago
They gave A = B+C, A+B = 10Days, C=50 Days;
A+B = 1/10;
since A = B+C;
B+C+B = 1/10;
2B+C = 1/10;
2B+1/50 = 1/10;
therefore B = 1/25;
B can complete in 25 days.
A+B = 1/10;
since A = B+C;
B+C+B = 1/10;
2B+C = 1/10;
2B+1/50 = 1/10;
therefore B = 1/25;
B can complete in 25 days.
(14)
Mohanapriyadarshini said:
1 decade ago
@awoke
How come 2 b's ?
A + B = 1/10 but A = B + C, then
A + B = B + B + C = 1/10 and C = 1/50
a value is a+b ,what about b+c, why you are adding b+b+c ?
How come 2 b's ?
A + B = 1/10 but A = B + C, then
A + B = B + B + C = 1/10 and C = 1/50
a value is a+b ,what about b+c, why you are adding b+b+c ?
PRAVEEN. P said:
8 years ago
A+B=1/10.
C=1/50.
A+B+C=6/50.
But A=B+C.
B+C+B+C=6/50.
2B+2C=6/50.
But C=1/50.
On substitute c in above eqn we get as,
2B=4/50 and,
B=1/25,
Hence B=25 days.
C=1/50.
A+B+C=6/50.
But A=B+C.
B+C+B+C=6/50.
2B+2C=6/50.
But C=1/50.
On substitute c in above eqn we get as,
2B=4/50 and,
B=1/25,
Hence B=25 days.
EKTA said:
1 decade ago
1/A=1/B+1/C......I.
1/A+1/B=1/10...II.
1/C=1/50.....III.
PUT 1/A=1/B+1/C IN EQ II.
1/B+1/C+1/B=1/10
2/B+1/50=1/10
2/B=10-1/50
2/B=4/50
1/B=1/25
B=25.
1/A+1/B=1/10...II.
1/C=1/50.....III.
PUT 1/A=1/B+1/C IN EQ II.
1/B+1/C+1/B=1/10
2/B+1/50=1/10
2/B=10-1/50
2/B=4/50
1/B=1/25
B=25.
Tenacious Guy said:
8 years ago
It can also go like this,
Since A=B+C.
So Add B on both sides you get.
A+B = 2B+C.
Solve it. 1/10 = 2B+1/50.
1/10 - 1/50.
4/50 = 2B.
B = 1/25.
25 Days.
Since A=B+C.
So Add B on both sides you get.
A+B = 2B+C.
Solve it. 1/10 = 2B+1/50.
1/10 - 1/50.
4/50 = 2B.
B = 1/25.
25 Days.
Suresh said:
1 decade ago
From given statement
A+B+C = 6/50 ( A+B = 1/10 and C = 1/50)
Substitute A= B+C in above equation to get A= 3/50
3/50+B+1/50 = 6/50
B = 1/25
25 days
A+B+C = 6/50 ( A+B = 1/10 and C = 1/50)
Substitute A= B+C in above equation to get A= 3/50
3/50+B+1/50 = 6/50
B = 1/25
25 days
Post your comments here:
Quick links
Quantitative Aptitude
Verbal (English)
Reasoning
Programming
Interview
Placement Papers