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.
Mehedy said:
1 decade ago
A can 23 days.
B can (23+23*30/100) = 29.9.
A 1 day = 1/23.
B 1 day = 1/29.9.
So (1/23+1/29.9) = 52.9/687.7 = 1/13 = 13.
B can (23+23*30/100) = 29.9.
A 1 day = 1/23.
B 1 day = 1/29.9.
So (1/23+1/29.9) = 52.9/687.7 = 1/13 = 13.
Ravi said:
1 decade ago
@Sk Gopinath Siva.
I don't get the way you added those fractions so could you please explain little bit more clear?
I don't get the way you added those fractions so could you please explain little bit more clear?
Anshuman said:
1 decade ago
We have to solve this in this way also since A is 30 % more efficient than B it means.
A = B+B*3/100 i.e. A = 1.3B.
A = B+B*3/100 i.e. A = 1.3B.
Runsi said:
1 decade ago
A is 1 days's work is 1/23 which is given in the sum and B's 1 day's work we got. Add both then we get the result
Adithi said:
1 decade ago
A=1/23.
A=1.3B.
So B=1/(23*130/100).
B=10/(23*13).
A+B=1/23+1/(10/(23*13)).
So A+B=1/13.
Answer is 13 days.
A=1.3B.
So B=1/(23*130/100).
B=10/(23*13).
A+B=1/23+1/(10/(23*13)).
So A+B=1/13.
Answer is 13 days.
Badal said:
7 years ago
E * d = w,
So, the Total work 13 * 23,
Together efficiency = 23.
So, (13 * 23)÷23 = 13 is the answer.
So, the Total work 13 * 23,
Together efficiency = 23.
So, (13 * 23)÷23 = 13 is the answer.
Divyanshu yadav said:
7 years ago
B's days to complete the work=days taken by A+30% of days taken by A.
= 23+ (30/100) *23= 29.9 days.
= 23+ (30/100) *23= 29.9 days.
Krish Sapkota said:
9 years ago
I think ratio taken may be wrong (100 : 130). it should be 130 : 100.
Please confirm it guys.
Please confirm it guys.
Nayana said:
1 decade ago
In the problem while adding A+B why they have written 10/299 instead of writting 299/10 ?
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??
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