Aptitude - Time and Work - Discussion
Discussion Forum : Time and Work - General Questions (Q.No. 17)
17.
A is 30% more efficient than B. How much time will they, working together, take to complete a job which A alone could have done in 23 days?
Answer: Option
Explanation:
Ratio of times taken by A and B = 100 : 130 = 10 : 13.
Suppose B takes x days to do the work.
Then, 10 : 13 :: 23 : x  x = |
 |
23 x 13 |  |
x = |
299 | . |
| 10 | 10 |
| A's 1 day's work = | 1 | ; |
| 23 |
| B's 1 day's work = | 10 | . |
| 299 |
| (A + B)'s 1 day's work = | |
1 | + | 10 | |
= | 23 | = | 1 | . |
| 23 | 299 | 299 | 13 |
Therefore, A and B together can complete the work in 13 days.
Discussion:
119 comments Page 1 of 12.
AJAY D said:
1 week ago
A - 130.
B - 100.
130 23.
100 B.
130 * 23 = 100 * B,
130 * 23/100 = B.
A + B = 1/23 + 100/130 * 23.
= 130/130 * 23 + 100/130*23,
= 130 + 100/130 * 23,
= 230/130 * 23,
A + B = 1/13.
B - 100.
130 23.
100 B.
130 * 23 = 100 * B,
130 * 23/100 = B.
A + B = 1/23 + 100/130 * 23.
= 130/130 * 23 + 100/130*23,
= 130 + 100/130 * 23,
= 230/130 * 23,
A + B = 1/13.
Bhargav said:
3 weeks ago
Let me assume supposed if A's efficiency is 100% then B's efficiency is 70%of A.
So,
Here given efficiency of A = 1/23
So B's efficiency is = 1/23(0.7),
= 7/230.
Now A+B work together;
So, 1/23+7/230.
= 17/230.
So the total no of days where A and B work together is 230/17.
Why isn't this answer is correct? plz, anyone explain.
So,
Here given efficiency of A = 1/23
So B's efficiency is = 1/23(0.7),
= 7/230.
Now A+B work together;
So, 1/23+7/230.
= 17/230.
So the total no of days where A and B work together is 230/17.
Why isn't this answer is correct? plz, anyone explain.
Barsa rani behera said:
9 months ago
30% = 30/100.
100 = B.
Efficiency A. 13
B.10.
Total 13 + 10 = 23.
Total. 13 * 23 = 299.
A + B = 13 * 23/23 = 13days.
100 = B.
Efficiency A. 13
B.10.
Total 13 + 10 = 23.
Total. 13 * 23 = 299.
A + B = 13 * 23/23 = 13days.
(5)
Dhvani said:
1 year ago
A = 130 %
B = 100%
Per day A's work = 1.3.
Per day B's work = 1.
Together means 1 + 1.3 = 2.3.
So,
1.3 = 1/23,
2.3 = ?.
By cross multiplication,
= (23 * 1/23)/13.
= 1/13.
= Reverse of 1/13.
= 13 days.
We get the answer as 13 days.
B = 100%
Per day A's work = 1.3.
Per day B's work = 1.
Together means 1 + 1.3 = 2.3.
So,
1.3 = 1/23,
2.3 = ?.
By cross multiplication,
= (23 * 1/23)/13.
= 1/13.
= Reverse of 1/13.
= 13 days.
We get the answer as 13 days.
(17)
SAITEJA VOTARIKARI said:
2 years ago
A = 130 %
B = 100%
Per day A's work = 1.3
Per day B's work = 1.
Together means 1 + 1.3 = 2.3.
So,
2.3 = 23
1.3 =?.
By cross multiplication, we get the answer 13.
B = 100%
Per day A's work = 1.3
Per day B's work = 1.
Together means 1 + 1.3 = 2.3.
So,
2.3 = 23
1.3 =?.
By cross multiplication, we get the answer 13.
(24)
Janu said:
2 years ago
A is 30% efficient than B,
Then,
A = 30% + B.
A's 1 day work = 1/23.
Let, take B work as x, then B's 1 day work is 1/x.
A = 30% + B.
1/23 = 30% + 1/x.
1/23 = ( 30/100 * 1/x) + 1/x,
1/23 = 13/10x,
x = 299/10,
1/A + B = 1/23 + 10/299,
A + B = 13.
Then,
A = 30% + B.
A's 1 day work = 1/23.
Let, take B work as x, then B's 1 day work is 1/x.
A = 30% + B.
1/23 = 30% + 1/x.
1/23 = ( 30/100 * 1/x) + 1/x,
1/23 = 13/10x,
x = 299/10,
1/A + B = 1/23 + 10/299,
A + B = 13.
(16)
Naveen said:
3 years ago
A-> ( 100% = 23).
B->(130% = x).
Cross multiple:
100x = 23×130.
x = 23×130/100,
x = 299/10.
A + B-> 1/23 + 10/299.
13+10/299.
23/299.
Ans->13.
B->(130% = x).
Cross multiple:
100x = 23×130.
x = 23×130/100,
x = 299/10.
A + B-> 1/23 + 10/299.
13+10/299.
23/299.
Ans->13.
(25)
Logesh said:
4 years ago
(A+B) will complete the work in;
=Total work eff. of(A+B)=13 * 23/10+13,
=13 days.
=Total work eff. of(A+B)=13 * 23/10+13,
=13 days.
(9)
Prachi said:
4 years ago
A is 30% more efficient than B.
So, Assume 100: 130.
then ratio is 10:13.
Now cross multiple the value 10:13.
23:x..........(23 day)
13*23/10 = 299/10.
A=1/23,B = 299/10.
i.e 1/23 + 10/299 = 23/299 = 1/13.
So, Assume 100: 130.
then ratio is 10:13.
Now cross multiple the value 10:13.
23:x..........(23 day)
13*23/10 = 299/10.
A=1/23,B = 299/10.
i.e 1/23 + 10/299 = 23/299 = 1/13.
(8)
S. Kalyan said:
5 years ago
A is 30% more efficient than B.
This means;
A ------------ B
100%--------- 130%
Now this 100% of work done by A in 23days.
Now
100% ---------------------> 23.
130%----------------------> x.
By Cross Multiplication We get;
100% * x = 23 * 130%,
=> (100/100) * x = 23 * (130/100),
=> x = 23 * (13/10),
=> x= (299/10),
this X work now we got is B's Total Work.
Now Calculate A & B work Together.
ie. (A+B)'s 1 day Work = (1/24) + (10/299)/ LCM is 299.
On Calculating we get answer = 23/299 = 1/13.
So, They Took 13 days to Complete the Work.
This means;
A ------------ B
100%--------- 130%
Now this 100% of work done by A in 23days.
Now
100% ---------------------> 23.
130%----------------------> x.
By Cross Multiplication We get;
100% * x = 23 * 130%,
=> (100/100) * x = 23 * (130/100),
=> x = 23 * (13/10),
=> x= (299/10),
this X work now we got is B's Total Work.
Now Calculate A & B work Together.
ie. (A+B)'s 1 day Work = (1/24) + (10/299)/ LCM is 299.
On Calculating we get answer = 23/299 = 1/13.
So, They Took 13 days to Complete the Work.
(7)
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