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 9 of 12.
Rahul said:
1 decade ago
@Pallavi.
He will complete his remaining work in 5 days.
He will complete his remaining work in 5 days.
Pallavi said:
1 decade ago
A person can do 1/6th of the work in 2 days. If he now works 50% faster, in how many days can he finish the remaining work ?
Jeetu said:
1 decade ago
I agree with Shahid basha.
According to the language used in the above question base should be B's efficiency and not A's because in the given explanation to the question 100 is 76% approx of 130 and not 70% (100%-30%) as required.
According to the language used in the above question base should be B's efficiency and not A's because in the given explanation to the question 100 is 76% approx of 130 and not 70% (100%-30%) as required.
Ammulu ch said:
1 decade ago
How 230%? Please explain clearly.
Shiva said:
1 decade ago
23 days------------>130%.
? days------------->230%.
130/230*23 = 13 days.
? days------------->230%.
130/230*23 = 13 days.
Ramesh said:
1 decade ago
Why should we use the days as A = 100 and B = 130? Cant we use it as A = 30 and B = 60?
Swati said:
1 decade ago
Let no of days taken by A = x and by B = y.
Then, (y-x)/y = 30/100.
Gives x:y = 7:10.
Not 10:13.
Please help me in this.
Then, (y-x)/y = 30/100.
Gives x:y = 7:10.
Not 10:13.
Please help me in this.
Amrith said:
1 decade ago
@shakthi.
Then A's efficiency(A/C to question) = x+x*(30/100) = 13x/10....(2).
They are telling that a is 30% more efficient than b right. So it will be A=30/100 + x right....why x is multiplies with 30/100.
Then A's efficiency(A/C to question) = x+x*(30/100) = 13x/10....(2).
They are telling that a is 30% more efficient than b right. So it will be A=30/100 + x right....why x is multiplies with 30/100.
Dawood Sheriff said:
1 decade ago
Actually A is more efficient than B as per the question,
Then A could be 130% of B.
B = 10/13*23=230/13.
A = 1/23 ,for a day.
B = 230/13, for a day.
Therefore (A + B)T = 1.
(13/230 + 1/23)T = 1.
T = 10.
Then A could be 130% of B.
B = 10/13*23=230/13.
A = 1/23 ,for a day.
B = 230/13, for a day.
Therefore (A + B)T = 1.
(13/230 + 1/23)T = 1.
T = 10.
Javid mir said:
1 decade ago
A = 23 days.
B = 30%more than A i.e, B=130% of A.
B = 130/100*23 = 299/10.
Now, A's 1 day work = 1/23.
B's 1 day work = 10/299.
Therefore, (A+B) completes 1 days work in (t)=1/23 + 10/299.
Solving for (t) we get, t=1/13.
t=13.
B = 30%more than A i.e, B=130% of A.
B = 130/100*23 = 299/10.
Now, A's 1 day work = 1/23.
B's 1 day work = 10/299.
Therefore, (A+B) completes 1 days work in (t)=1/23 + 10/299.
Solving for (t) we get, t=1/13.
t=13.
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