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:
146 comments Page 3 of 15.
Anchal said:
1 decade ago
Best method is Awoke method, because this is shortcut for doing in competative exams. But for understandin the solution, we can see Nagu's method.
So good job have done by both the guys. Thankyou.
So good job have done by both the guys. Thankyou.
Nagu said:
1 decade ago
Hi Guys, sorry for the late and here is the explanation about you doubt.
In my previous explanation I mentioned
(a+b+c)'s one day work = 3/25
and a+b+c = 2a here b+c=a means a's one day work = b+c's one day work
then a's one day work+(b+c)'s one day work = 3/25
so a+a = 3/25
2a = 3/25
so here 2* a's one days work = 3/25
So I think u can under stand now
keep practicing.....
In my previous explanation I mentioned
(a+b+c)'s one day work = 3/25
and a+b+c = 2a here b+c=a means a's one day work = b+c's one day work
then a's one day work+(b+c)'s one day work = 3/25
so a+a = 3/25
2a = 3/25
so here 2* a's one days work = 3/25
So I think u can under stand now
keep practicing.....
DHARMENDRA said:
1 decade ago
A=B+C-----------------(1)
A+B=1/10--------------(2)
C=1/50----------------(3)
(1)+(2)
(B+C)+B=1/10-----------(4)
(3)+(4)
B+(1/50)+B=1/10
2B=(1/10)-(1/50)
B=1/25
SO B COMPLETE THE TASK IN 25 DAYS
A+B=1/10--------------(2)
C=1/50----------------(3)
(1)+(2)
(B+C)+B=1/10-----------(4)
(3)+(4)
B+(1/50)+B=1/10
2B=(1/10)-(1/50)
B=1/25
SO B COMPLETE THE TASK IN 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
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 ?
Nikhil said:
1 decade ago
Mr.Awoke your method is awesome and moreover its applicable to all such type of probs...thanks!
Pavan@9966606261 said:
1 decade ago
A=B+C;
A+B=1/10;
A-B=1/50;
2A=1/10+1/50=6/50;
A=3/50;
A-B=1/50;
B=3/50-1/50;
B=1/25;
B ALONE CAN DO IN "25" DAYS
A+B=1/10;
A-B=1/50;
2A=1/10+1/50=6/50;
A=3/50;
A-B=1/50;
B=3/50-1/50;
B=1/25;
B ALONE CAN DO IN "25" DAYS
Sowmya said:
1 decade ago
@awoke.
Your method is awesome.
Your method is awesome.
Rakesh sonowal said:
1 decade ago
A=B+C (1)
A+B 1 Day work=1/10 (2)
Cs 1 Day work=1/50 (3)
putin eq (1) n (3) in eq (2)
2B +1/50=1/10
2B=1/10-1/50
2B=(5-1)/50
2B=4/50
B=4/50 =1/25
So Bs 1 day work =1/25.
So B alone could do d work in 25 days.
A+B 1 Day work=1/10 (2)
Cs 1 Day work=1/50 (3)
putin eq (1) n (3) in eq (2)
2B +1/50=1/10
2B=1/10-1/50
2B=(5-1)/50
2B=4/50
B=4/50 =1/25
So Bs 1 day work =1/25.
So B alone could do d work in 25 days.
GAURAV said:
1 decade ago
TIME FOR CERTAIN WORK....
A=B+C .....................................i
FOR
A+B=10 DAY.......SO(A+B)_1DAY WORK=1/10
.>A=1/10-B.......................ii
C=50 DAY.........1 DAY C WORK=1/50......................iii
SO ...FOR B=A-C.........................FROM i
B=1/10-B-1/50
2B=1/10-1/50
B=1/25
.........SO B REQUIRE 25 DAYS
A=B+C .....................................i
FOR
A+B=10 DAY.......SO(A+B)_1DAY WORK=1/10
.>A=1/10-B.......................ii
C=50 DAY.........1 DAY C WORK=1/50......................iii
SO ...FOR B=A-C.........................FROM i
B=1/10-B-1/50
2B=1/10-1/50
B=1/25
.........SO B REQUIRE 25 DAYS
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