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:
120 comments Page 10 of 12.
Hamsa said:
1 decade ago
Here why dont we use shortcut formula (K*X)/{(k^2)-1}???.
Can any one clear my doubt??
Can any one clear my doubt??
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?
Logesh said:
5 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)
Shiva said:
1 decade ago
23 days------------>130%.
? days------------->230%.
130/230*23 = 13 days.
? days------------->230%.
130/230*23 = 13 days.
ALLU said:
8 years ago
Efficiency and time are inversely proportional.
1/23 +1/(23*1.3)=1/x.
x = 13.
1/23 +1/(23*1.3)=1/x.
x = 13.
Sonam said:
8 years ago
A=130 and B=100.
The efficiency A=13, B=10,
A=23 * 13,
A+B=23*13/23=13.
The efficiency A=13, B=10,
A=23 * 13,
A+B=23*13/23=13.
Shirisha said:
2 decades ago
I think it is 100:30 ans is wrong please explain how it is 100:130?
Gaurav said:
10 years ago
Is any shortcut there to solve the problem? Please share with me.
Shakeena said:
1 decade ago
299/10 is the one day work, so reciprocal is the days taken.
Rahul said:
1 decade ago
@Pallavi.
He will complete his remaining work in 5 days.
He will complete his remaining work in 5 days.
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